r7¥/030’

LIBRARY
Michigan State
University

This is to certify that the
thesis entitled

The Characterization of Match Head Based Improvised
Explosive Devices

presented by

Jeffrey Harrison Dake

has been accepted towards fulfillment
of the requirements for the

MS. degree in Forensic Science

\

 

/ alajor 7&5 H’s Signature

1/, o”;

Date

' I

MSU is an Aifinnative Action/Equal Opportunity Institution

v.-.-u-.-.-._._

 

PLACE IN RETURN BOX to remove this ched<out from your record.
TO AVOID FINES return on or before date due.
MAY BE RECALLED with earlier due date if requested.

 

DATE DUE

DATE DUE

DATE DUE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2/05 mlCfiC/DetoDueindd-nts

 

THE CHARACTERIZATION OF MATCH HEAD BASED
MPROVISED EXPLOSIVE DEVICES

By

Jeffrey Harrison Dake

A THESIS

Submitted to
Michigan State University
In partial fulfillment of the requirements
For the degree of

MASTER OF SCIENCE IN FORENSIC SCIENCE
School of Criminal Justice

2005

ABSTRACT

THE CHARACTERIZATION OF MATCH HEAD BASED
IMPROVISED EXPLOSIVE DEVICES

By
Jeffrey Harrison Dake

An important aspect in the analysis of improvised explosive devices (IEDs) is the
identification of the explosive load used. Currently, very little information has been
published on the characterization of IEDs employing matches as the primary explosive
load. Many analytical methods have been shown to be effective in the characterization of
the various components found in matches. Little has been published on the identification
of these components in the complex deflagration products often encountered in post blast
residues. Detection of unconsumed material has been demonstrated by scanning electron
microscopy with various elements being identified (Glattstein et a1, 1991). Using
established methods of explosive residue analysis, asystem was implemented to analyze
the materials recovered from post blast debris of match head based IEDs. The combined
physical and chemical properties were used to create a classification scheme for match
head based explosive IEDs, which would also eliminate most other low explosive
mixtures as possible explosive loads in the recovered debris from an IED. In addition, an
examination of fragmentation patterns was performed on the recovered PVC device
fragments. Physical characteristics and size groupings of the fragments were observed in
an attempt to correlate fragmentation patterns with preparation methods of the match
heads used in the IEDs. The results of this study can ultimately be used to compile more
specific class information from exploded bomb fragments characteristic to match head

devices.

For Amber

iii

ACKNOWLEDGEMENTS

I would like to thank Jamie Crippin for allowing me to perform this research for
him, as well as supporting the preliminary work on this project. Thanks are also in order
to Dr. Jay Siege] for his direction and support through all of my graduate studies. I
would also like to thank Guy Nutter and Dr. Vincent Hoffman for serving on my thesis
committee. Thanks to the WFLETC, Pueblo Police Department Bomb Squad, and the
Michigan State Police Crime Laboratory for the use of their facilities and expertise.

I would like to express my gratitude to everyone who has been a teacher to me,
both in and out of the classroom. In particular I would like to thank Jan Stemberg and
Tom Seay for teaching me, among other things, the true definition of discipline; without
which I would never have achieved my goals.

Thanks to my fiiends who have supported me in my endeavors. Most importantly
I would like to thank my parents, who have shown an unshakable faith in my abilities and

potential.

iv

TABLE OF CONTENTS

LIST OF TABLES ............................................................................................................. vi
LIST OF FIGURES .......................................................................................................... vii
INTRODUCTION .................................................................................. . ............................. 1
EXPERIMENTAL ............................................................................................................... 7
Instrumentation and Materials ................................................................................. 7
Experimental Design .............................................................................................. 10
RESULTS .......................................................................................................................... 13
Soil Standards and Match Head Reference Standards ........................................... 13
Physical Examinations ........................................................................................... 23
Microcrystal and Microchemical Examinations .................................................... 27
Instrumental Examinations .................................................................................... 32
DISCUSSION .................................................................................................................... 47
Physical Examinations ........................................................................................... 47
Microcrystal and Microchemical Examinations .................................................... 53
Instrumental Examinations .................................................................................... 5 7
CONCLUSIONS ................................................................................................................ 62
FUTURE WORK ............................................................................................................... 66
REFERENCES .................................................................................................................. 67

LIST OF TABLES

Table 1. List of all samples treated as unknowns in this study, their sample designations,
match type used, and preparation method used ...................................... . ............................. 8

Table 2. Experimental results from the microcrystal and microchemical examinations of
the match head exemplars and the soil control samples .................................................... 14

Table 3. Experimental results from the FT IR and IC examinations of the match head
exemplars and the soil control samples ............................................................................. 16

Table 4. List of all materials recovered from sample IEDs as well as important physical
observations of sample IEDs, black powder, and smokeless powder exemplars .............. 24

Table 5. Experimental results from the microcrystal and microchemical examinations of
the materials recovered from the sample IEDs .................................................................. 30

Table 6. Experimental results from the FTIR and IC examinations of the materials
recovered from the sample IEDs ........................................................................................ 33

vi

LIST OF FIGURES

Figure 1. FT IR spectra of crystals recovered from the aqueous extracts of the wooden
“safety” match exemplar. Both the consumed and unconsumed materials are represented.
Note the presence of absorption bands at 970 cm”1 and 940 cm'1 characteristic of
potassium chlorate ............................................................................................................. 17

Figure 2. IC chromatograms of aqueous extracts from the “strike anywhere” match
exemplar. A. Chromatogram of the extract from the unconsumed material. B.
Chromatogram of the extract from the consumed material ............................................... 18

Figure 3. FT IR spectra of crystals recovered from the aqueous extracts of the soil
control samples. Note the absences of the absorption bands at 970 cm'1 and 940 cm”. A.
The FT IR spectra of the “School” soil sample. B. The FTIR spectra of the “Range” soil
sample ................................................................................................................................ 19

Figure 4. IC chromatograrn of the aqueous extract from the “School” control soil
sample. Note the absence of a chlorate peak .................................................................... 21

Figure 5. IC chromatograrn of the aqueous extract from the “Range” control soil sample.
Note the absence of a chlorate peak and the high concentration of sulfates ...................... 22

Figure 6. Examples of the oxidation observed on the threads and caps of the steel IEDs
post-blast. The top pipe and cap are fi'om sample 82B, the bottom pipe and cap are from
sample S4 ........................................................... 26

Figure 7. Examples of the fracturing observed in the fragments of the PVC IEDs. The
fiagment on the left is fi‘om sample P3, the fragment on the right is from sample
PSmokeless. Note that while some minor fractures are observed in the fragment from the
P3 sample IED, extensive fracturing is observed in the fragment from the PSmokeless
IED ..................................................................................................................................... 28

Figure 8. Plot of the percentages of total fragments in each size grouping for all
unknown PVC samples, as well as the two PVC exemplars. Note that only samples P1,
P13, P6 and P63, display significant differences in size distributions from the other
unknown samples ............................................................................................................... 29

Figure 9. FT IR spectra of the aqueous extracts of the three material types recovered

fi'om sample P4. Note that only the unconsumed material extract displays the
characteristic 970 cm“1 and 940 cm'l peaks associated with potassium chlorate .............. 37

vii

LIST OF FIGURES, CONTINUED

Figure 10. IC Chromatogram of the standard sample run in the Anion method. Retention
times of the 8 standard anions are displayed in minutes. Fluoride (3.4), chloride (5.9),
nitrite (7.4), bromide (9.7), chlorate (10.4), nitrate (11.4), phosphate (15.2), and sulfate
(17.2) .................................................................................................................................. 38

Figure 11. IC chromatograms of the aqueous extracts fiom the three material types
recovered from sample P7. The sulfate peak is unlabeled in Figure 11a, but comparison
with standard chromatograms indicates that the peak near 17 minutes is sulfate. A.
Chromatogram of the extract fi'om the unconsumed material. B. Chromatogram of the
extract from the consumed material. C. Chromatogram of the extract fiom the residue
material .............................................................................................................................. 40

Figure 12. FT IR spectra of the aqueous extracts of the three material types recovered
from sample S3B. Note that only the unconsumed material extract displays the
characteristic 970 cm’1 and 940 cm'1 peaks associated with potassium chlorate .............. 42

Figure 13. IC chromatograms of the aqueous extracts from the three material types
recovered from sample S3B. Note the small unlabeled peak near 15 minutes in the
unconsumed extract, indicating detection of phosphates. A. Chromatogram of the
extract from the unconsumed material. B. Chromatogram of the extract from the
consumed material. C. Chromatogram of the extract from the residue ........................... 43

Figure 14. IC chromatograrn of the aqueous extract from the residue of sample P2B.

The peak at 9.6 minutes was identified as bromide by comparison with a standard
spectrum. The peak near 23 minutes was unidentifiable by comparison with a standard
spectrum ............................................................................................................................. 46

Figure 15. Photograph displaying the residue color from samples P4 (left) and
PBlackPowder (right). Note the red-orange color of the P4 sample and the gray color of
the PBlackPowder sample .................................................................................................. 48
Figure 16. Photomicrograph of recovered intact match heads from various devices ...... 50
Figure 17. Photomicrograph of chipped match head material (left) and a flake of Red

Dot commercial smokeless powder (right). Note the differences in shape, color, and
luster in the two samples .................................................................................................... 51

viii

INTRODUCTION

Very little research has been done on improvised explosive devices, or [EDs,
utilizing match heads as an explosive load. As matches are readily available to virtually
any individual, they present a convenient explosive for IEDs. Therefore, it is important
for characterization information to be made available to forensic scientists who may
receive these types of samples in casework.

Robert Boyle first developed matches when he discovered that mechanical
mixtures of sulfur and phosphorus would ignite when subjected to friction. Early
matches used a form of white phosphorus that proved highly toxic, and in 1845 it was
replaced with the safer red phosphorus, or phosphorus sesquisulfide. Early matches
contained the sulfur in a binder with a small tip of red phosphorus, butthese were prone
to unexpected combustion. This problem was alleviated by Carl Lundstrom who placed
the red phosphorus on a friction strip, creating the first “safety” matches. Presently, the
formula for matches has become relatively uniform with phosphorus sesqisulfide and
sulfur being the primary elements. The other components used in the binder and coloring
include: animal glue, starch, dextrin, potassium chlorate, zinc oxide, calcium carbonate,
diatomaceous earth, siliceous filler, a potassium chromate or lead burning rate catalyst,
powdered glass, dammar gum, and paraffin. “Safety" match tips contain the sulfirr
compound in a binder. The phosphorus is contained in the striking surface on the
package to prevent accidental combustion of the match, and “safety” matches require
friction between the match end and the striker for ignition. “Strike anywhere” matches
consist of sulfur contained in a binder on the match end, with a small tip of phosphorus

sesquisulfide contained in a binder. These matches contain both of the chemical elements

for combustion on the tip, and require only fiiction for ignition. Currently, “strike
anywhere” matches are no longer being produced in the United States;~ however, they are
still imported and can easily be obtained.

It has been demonstrated that scanning electron microscopy—energy dispersive x-
ray spectroscopy can detect and characterize the residues of “safety” matches on the
interiors of pipe fragments from exploded IED’s (Glattstein, Landau, and Zeichner,
1991). Their analysis was restricted to elemental analysis by SEM-EDS, in which the
following elements were successfirlly identified: chlorine, potassium, sulfur, silicon,
calcium, titanium, magnesium, zinc, chromium, aluminum, and iron. This experiment
has demonstrated that it is possible to detect residues fi'om match heads on exploded
bomb fragments. The major drawback to this approach is that SEM-EDS is a method of
particle analysis. Often in the analysis of explosive debris, the explosive residues are
extracted from debris in a matrix. In light of this, it would be preferable to incorporate a
chromatographic technique which would be able to separate the match head components
fi'om the matrix.

Bevcridgc et al. developed a system for the analysis of explosive residues which
utilizes a combination of techniques to characterize the explosive loads used in various
IEDs (Beveridge et al., 1975). The analytical scheme employs morphological
examinations, crystal structure examinations, chromatographic techniques, and several
instrumental methods for the identification of components in the residues. More recently,
the Technical Working Group for Fire and Explosions (TWGFEX) has created guidelines
for the identification of intact explosives. TWGFEX identifies four categories of

techniques for the analysis of explosives; category 1 techniques provide significant

structural and/or elemental composition, category 2 techniques provide limited structural
and/or elemental composition, category 3 techniques provide a high degree of selectivity,
and category 4 techniques are useful but do not fall into one of the other categories
(TWGFEX, pg 1-2). In its guidelines, TWGFEX states that a category 1 technique is
sufficient for identification, while a category 2 technique requires one additional
technique and a category 3 technique requires two additional techniques for
identification. In addition to the listed techniques, the guidelines emphasize the
morphological examination of recovered explosives as a means for suggesting further
analysis. In a separate document by TWGFEX, methods for the training of explosives
analysts are outlined. The importance of a physical examination of the debris recovered
from pyrotechnic devices is discussed as an important means of directing further
analytical methods (TWGFEX, pg 23-24). Physical characteristics suCh as visual
observations, size, and odor are identified as being of probative value in the analysis of
unknowns.

Using the systems presented by Beveridge et al., an analytical scheme was
designed to detect the various components of commercial matches and their deflagration
products, with particular emphasis on the characterization of sulfur, phosphorus
sesquisulfide, and potassium chlorate. TWGF EX guidelines for the analysis of intact
particles were adhered to for sufficient identification of explosive materials. The
techniques selected were the following; Fourier transform infrared spectrophotometry
(FT IR) a category 1 technique, ion chromatography (IC) 3 category 3 technique, and
polarizing light microscopy (PLM) a category 3 technique. The TWGFEX guidelines

state that if two different microscopy examinations (such as microchemical tests and

microcrystal tests) are employed, they may count as two of the three required techniques
for category 3 identification. In addition, a morphological examination was included in
the analytical scheme.

The initial visual examination is of great importance in trace evidence analyses,
and the examination of explosive debris is no exception. Washington and Midkiff
reported characterization of explosives by morphological examination of unconsumed
material in 98% of the samples that were identified in their analytical scheme
(Washington and Midkiff, 1972). As the combustion material found in matches often has
a color imparted to the mixture, morphological examinations may be an effective
presumptive method that will provide valuable probative information.

The detection of potassium chlorate by aqueous recrystalization is possible
utilizing polarized light microscopy to identify diamond shaped crystals of low order
birefringence (Hopen and Kilbourn, 1985). The detection of potassium chlorate is
significant in the analysis of match head based IEDs, as potassium chlorate has been
banned in most commercial propellants and pyrotechnic mixtures produced in the United
States. Because of this ban, no commercial low explosives or pyrotechnic mixtures
produced in the United States, with the exception of matches, should contain potassium
chlorate. IR has also been shown to be an effective method of characterizing potassium
chlorate (Miller and Wilkins, 1952). In addition, FTIR may be useful in detecting
organic components used in the binder material of commercial matches.

A separation technique was added to the analytical scheme to account for the
complex mixtures often encountered in explosive loads and residues. Ion

chromatography was selected for its low limits of detection, and its ability to separate and

detect various anionic compounds. The detection of chlorates supports microcrystal and
FTIR results, as well as complement microchemical results in the detection of potassium
chlorate. In addition, ionic reaction products from the deflagration process are expected
and may be detectable by IC.

The first goal of this study is to attempt to identify characteristic fragmentation
patterns related to the various preparations of match head based explosive loads. There is
a possibility that various load types and the methods with which the filler is prepared will
alter the brisance, or shattering power, of the IEDs. While there is no direct method for
measuring brisance, it is expected that visible differences will be identified in both the
fragment sizes and the fragmentation patterns of the devices with the varying brisances of
the different explosive loads (Manon, 1976). Devices that employ cut match heads will
have less actual explosive material than other devices, due to the presence of the wood or
paper match end within the head. Also, the “whole” nature of the cut match heads will
create air pockets within the devices, which should lower their ultimate brisance.

Devices that employ match heads where the material has been chipped or scraped fi'om
the wooden body will contain greater amounts of explosive load, as the wood or paper
match body will not be present. Due to the shape of the chipped fragments air pockets
will be present thus decreasing the amount of space occupied within the device, and
lowering the overall brisance. Devices containing ground match heads will utilize the
ideal amount of space within the device, and should result in the highest brisance devices.
Also, there is a possibility of change in brisance, either an increase or decrease, with the
variation of the type of match used in device construction. The presence of phosphorus

in the “strike anywhere” match heads will decrease the amount of sulfur in the device,

which may decrease the brisance. Conversely, the mixtures of sulfur and phosphorus
have a much lower ignition temperature than either individual element, and may lead to
more complete deflagration in the “strike anywhere” devices, and thus a higher brisance
charge. With greater brisance, more fragmentation is expected, and the type of
fragmentation may be indicative of the load type or method used in device construction.
The second goal of this study is to develop a system of analysis that will identify
morphological and chemical characteristics of match head based IEDs, which will
ultimately allow forensic analysts to identify a device as having employed matches as the
primary explosive load. Detection of two main components used in matches, sulfur and
potassium chlorate, will allow for differentiation of match head material fi'om other
commercial and improvised low explosives. Detection of phosphorus scsquisulfide, or a
degradation product thereof, may allow for differentiation between “strike anywhere” and

“safety” matches.

EXPERIMENTAL
Instrumentation and Materials

Samples were constructed and detonated at the Western Forensic Law
Enforcement Training Center in Pueblo, Colorado. Materials for sample construction
were purchased at hardware stores. The three different load types were prepared in the
following manners: The “cut” devices had the head of the match cut from the match stick
using wire cutters. The “chipped” devices had the match head material physically
removed from the stick using a combination of crushing the head and subsequent removal
with jeweler’s tweezers. The “ground” devices were prepared in the same manner as the
“chipped” devices with the match head material then being collected and placed in a glass
mortar and pestle and ground with methanol to decrease fiiction, the sample was then
dried, further ground, and sieved to remove gross wood particles. All devices were filled
to approximately three quarters of their total volume to facilitate deflagration.

Four inch steel pipes with 1.5 inch diameters and threaded ends were used for the
steel devices. The ends caps were 1.5 in diameter steel caps. A hole was drilled in one
end cap to allow for the insertion of the fuse. A four foot polyvinyl chloride (PVC) pipe
was cut into four inch long sections with a hacksaw for the PVC devices. An end cap
was glued to one end using PVC cement, and a threaded cap was glued to the other end
of each device. A threaded plug was then screwed into the threaded end, with a hole
drilled in the plug to allow for the insertion of the fuse.

The complete sample set represents both steel and PVC based devices utilizing

both safety and strike anywhere matches, as well as all three preparation types (Table 1).

Sample

Designation

P1,P1B
P2,PZB
P3.P38
P4,P4B
P5,P5B
P6,P6B
P7,P7B
$1,313
$2,828
$3,333
$4,343
$5,353
$6,868
$7,373

PIPO TYPO

PVC'
PVC
PVC
PVC
PVC
PVC
PVC
Steel
Steel
Steel
Steel
Steel
Steel
Steel

Match Type

Wooden Safety
Paper Safety
Wooden Safety
Strike Anywhere
Wooden Safety
Strike Anywhere
Strike Anywhere
Wooden Safety
Paper Safety
Wooden Safety
Strike Anywhere
Wooden Safety
Strike Anywhere
Strike Anywhere

Preparation

Method
Cut

Cut
Chipped
Chipped
Ground
Ground
Cut
Cut
Cut
Chipped
Chipped
Ground
Ground
Cut

Table 1. List of all samples treated as unknowns in this study, their sample
designations, match type used, and preparation method used

Reference samples of the wooden safety matches, paper safety matches, and
wooden strike anywhere matches were taken for analytical comparisons. Samples Pl ,
P2, S1, and 82 were all detonated at the Pueblo Police Department’s bomb range.
Samples of soil were collected prior to detonation to test for contamination. The samples
were buried in one foot of soil and detonated using an electric match. All of the other
samples were detonated in an open desert area on the edge of the Colorado State
University Pueblo campus. Soil samples were collected prior to detonation to test for
contamination. Samples were placed in one foot deep holes and covered with wooden
planks and sandbags, and were detonated with electric matches. All fragments were
collected by manually sitting and placed in plastic bags for storage and transport.
Samples SS and 858 were never received from WFLETC, and thus were not analyzed.

The microscopy was performed on an Olympus BX41 polarizing light microscope
(PLM), with a 530 nm full wave plate. Photomicrographs were taken with a Nikon
digital camera model DXMlZOOF attached to a Nikon SMZ8OO microscope, using the
Nikon Act 1 software in fine mode. Recrystalized materials from aqueous extractions
were run on a Perkin Elmer Spectrum One (FT IR) instrument in transmittance mode,
using scan averaging over 16 scans from 4000-650 cm'l. Aqueous extractions were also
run on a Dionex Dx-120 ion chromatograph (IC) equipped with an IonPac AS9-HC
4x250 mm Analytical column and an electrochemical detector. A 9 mM solution of
NazCO3 was used as the mobile phase. A sample amount of 25 uL was injected and the

sample was allowed to run for 25 minutes.

Experimental Design

In the first phase of the project, a system for the analysis of the reference samples
and soil samples was designed. Approximately 0.02 grams of each sample was placed in
a clean glass test tube, to which approximately a milliliter of chloroform was added. The
sample was then vortexed and allowed to settle. A drop of the chloroform solution was
placed on a microscope slide for examination by PLM. The edges of the drop were
observed as it evaporated and any crystal formations were documented. This process was
repeated up to three times to allow the sample to concentrate sufficiently, facilitating
crystal formation. The test tube was then placed on a hot plate to dry the sample. A
small amount of deionized water was placed in the dried test tube and the sample was
vortexed and allowed to settle. A drop of the water solution was placed on a slide for
examination by PLM. The edges of the drop were observed for any recrystalization as
the drop evaporated. The process was repeated up to three times to allow the sample to
concentrate, facilitating recrystalization. Representative crystals from the positive
controls were photographed using the stereomicroscope. Approximately half a milliliter
of the aqueous solution from the test tube was then placed in a vial to be analyzed by IC.
The samples were placed into sample vials with filter caps and loaded into cassettes for
auto sampling. An external standard was run at the beginning and end of each sample set
and a blank of deionized water was run in between each sample. The remainder of the
aqueous sample from the test tube was filtered using a syringe filter with a .45 um pore
size PETN filter to remove gross particulates. The filtrate was collected in a clean Petri

dish and dried on a hot plate. The dried crystals were then removed, placed in a mortar

10

with potassium bromide and ground. The sample was then pressed into a pellet and a
transmittance infrared spectrum was taken.

In the second phase of the experiment, the PVC and steel IED samples were
analyzed. The fragments were first visually examined both macroscopically and
microscopically for characteristic features. The fiagments for the PVC samples were
grouped into three size classes in an attempt to classify different filler types. All
measurements were taken with a ruler. The measurements were basedon the maximum
length and width of the fragments, and were labeled as: small (both sides smaller than .5
cm), medium (both sides between .5 cm and less than 1.5 cm), and large (at least one side
greater than or equal to 1.5 cm).

During the physical examination, any consumed or unconsumed material was
removed from the fragments physically and collected for chemical analysis. To obtain
the residue material from the steel pipes, the interior of the pipe was rinsed with
chloroform and collected in a test tube, and the pipe was allowed to dry. The interior was
then rinsed with warm deionized water to facilitate the extraction of the potassium
chlorate, and the rinse was collected in a test tube. To obtain the residue material from
the PVC fi'agments, the interior of the fragments was first washed with methanol, as
chloroform may extract plasticizers from the PVC surface. The methanol extraction was
then dried on a hotplate and the sample was reconstituted with a small amount of
chloroform. Aqueous extractions from the PVC fragments were performed in the same
manner as the steel fragments.

The consumed, unconsumed, and residue material from each sample was analyzed

using the methods developed in the first phase of the experiment. The purpose of these

11

experiments was to determine the effectiveness of the various methods in characterizing

the components from the explosive load present in match head based IEDs.

12

RESULTS

Images in this thesis are presented in color. All chromatograms presented in this
thesis may be compared with the standard in figure 10.
Soil Samples and Match Head Reference Standards

The results fi'om the microchemical and microcrystal tests performed on the
match reference standards and the soil background samples are included in Table 2. The
water recrystalization from all of the match standards, both unconsumed and consumed,
resulted in diamond shapes with low order birefringence indicative of potassium chlorate.
The platinum chloride microchemical tests resulted in the formation of hexagons with
three short sides and three long sides for all of the match references standards, indicating
the presence of potassium. Only 66% of the chloroform recrystalizations fiom the match
reference standards resulted in the formation of saw shaped crystals indicative of
elemental sulfur, while the consumed wooden “safety” match and the consumed “strike
anywhere” match standards resulted in unidentifiable crystal structures. The soil
background samples fi'om the CSU Pueblo site (referred to as School samples) gave no
appreciable crystals in either the water recrystalization or the chloroform recrystalization.
Some hexagons were identified in the platinum chloride microchemical tests, but they
were in a much smaller amount than those observed in the reference standards. The soil
background samples from the Pueblo Police bomb range (referred to as Range samples)
displayed a multitude of crystal structures in the water recrystalizations, with the
predominant structures observed being needles, clusters of needles, and crossed plates
indicative of ammonium nitrate. No diamond shapes were observed. The chloroform

recrystalizations from the Range samples gave no appreciable crystal structures. Some

13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sample Name H20 PTCL CHCL3
Recrystallzatlon Microchemical Recrystallzation

Wood Safety Whole Positive Positive Positive

Wood Safety Burnt Positive Positive lnconclusive
Paper Safety Whole Positive Positive Positive
Paper Safety Burnt Positive Positive Positive
Strike Anywhere Positive Positive Positive

Whole
Strike Anywhere Positive Positive lnconclusive
Burnt

School 1 Negative Slight Positive Negative
School 2 Negative Slight Positive Negative
School 3 Negative Slight Positive Negative
School 4 Negative Slight Positive Negative
School 5 Negative Slight Positive Negative
Range 1 Negative Negative Negative
Range 2 Negative Slight Positive Negative
Range 3 Negative Slight Positive Negative
Range 4 Negative Negative Negative
Range 5 Negative Slight Positive Negative

 

Table 2. Experimental results from the microcrystal and microchemical
examinations of the match head exemplars and the soil control samples.

14

 

hexagons were identified in the platinum chloride tests for 60% of the Range samples,
but the predominant crystal forms observed were burrs of needles and curved needles,
suggesting the presence of ammonium.

Results from the instrumental analyses of the match reference standards and the
soil background samples are presented in Table 3. In 66% of the match reference
standards, infrared absorptions at 970 cm"1 (dominant) and 940 cm'1 were identified by
FTIR spectroscopy, with the consumed wooden “safety" match and the consumed “strike
anywhere” match standards displaying no absorption bands in that region (Figure l).
Absorptions at these two wavelengths are indicative of potassium chlorate. Ion
chromatography of the unconsumed match samples detected the presence of chlorates,
chlorides, sulfates, and phosphates; with the “strike anywhere” standard containing
nitrates as well. In the unconsumed samples, chlorate was the most abundant anion
detected (Figure 2a). Ion chromatography of the consumed match reference standards
detected chlorates (except in the wooden “safety” standard), chlorides, sulfates,
phosphates, nitrates, nitrites, and bromides (only in the paper “safety” standard). The
concentrations of the chloride and sulfate anions were greater than in the unconsumed
samples, with the chloride anion being the most abundant anion detected (Figure 2b). In
the FTIR analyses none of the soil background samples, from the School set or the Range
set displayed absorption bands at 970 cm‘1 or 940 cm'1 (Figure 3a, 3b). Ion
chromatography of the School sample set detected chlorides, nitrates, sulfates, nitrites,
and phosphates (only in sample School 3), with sulfate being the most abundant peak in
each sample (Figure 4). Chlorides, nitrites, nitrates, and sulfates were detected in the

Range samples, with sulfate being the most abundant anion detected (Figure 5).

15

.8358
35:8 :8 2t wee man—@888 go: :89: 05 mo meoumegxo 2 98 ME.”— ofi 89a 3158 3:255me .m 033—.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3&8
9882 Rate 988 see was 988 9882 9882 m 88m
Gas
9882 9.:va 928a :35 Ed: 988 9882 9:82 v 88m
Ems
9882 3. SE 988 29: one 928; 9882 9882 m 8:9.
Que
9882 oak E 928; :55 8.9 988 9882 9882 N 88m
:38
9882 8.028 928a :36 25 928a 9=8oz 9882 F 88m
9882 :55 9.3 988 :35 mg 988 9882 9882 m 628
9882 :35 5.9 928; :35 R: 988 9882 98me 4 86m
$382? 988 SEE one 958a :35 8.: 928m 9:882 9:882 m 62.8
9:82 :55 moo: 9:58 :35 8.: 9E8“. 9882 9882 N 88m
9882 :55 Si 988 :32 o: 988 9882 9882 F 88m
3E8 :56
Eeoooé 938a :32 meat 9:68 8.02 5 958a :35 NE 92on 9882 26:55. 9.5.0.
222,
3.8%? 928.”. SEE 3.3 9281 see mo. 5 928a 8289 958m 928m 925% final
SEQ SHE 02:on :55
38.08% 988 8.2 5 928m 8.th 928m 3.625% 988 £95 8me 88m
33.8 29:5
8.835% 928; @883 928a :35 Re 988 9.8: 988 9=_8n_ .8me 88¢
.= E ESm
38.88% 928m 335 845 988 888 928; 9882 9882 8me 89>
222,
Rosemuoé 928a :35 8.: 928a :35 m: 938.“. 385509 988 928a .8me 89>
899;
8: 8888;; 6: 85:5 6: 880.5 6: «.2925 EH 282 macaw

 

 

 

 

 

 

 

16

38020 82888 no 0858820 780 ova 98
7.5 one 3 mega 83.8er me 8585 05 802 .880858 Be manage weasmeooes new 888:3 2: 50m
$3888 :32: .303: :38? 05 Mo 3858 38:3 2: 80¢ 33308 3836 mo «30% 5.: A charm

3.33 .. 9;: cc: 3% 93m Q83.

365.830 :352 .. spasm: c.5335

be...

36355:: 532 ..£u..am.. 523.5

17

n AN111704 #7 SA ECD 1
10;; S E“. , . . ,, ,__‘

‘4 - 10.607

57’
c.)

.U'
‘?
ALA ~LL 144. LA.

.9"
m
.LJ_L _ 4+

2.5 4

2 - 4.113
- chloride - 6.040

{um-11.901

u
:. 1 - 3.713

 

.1.0:7—~r—. . .« . f .77. . . . . . . .film"
0.0 5.0 10 0 15 O 20 0 25 0

Figure 2. IC chromatograms of aqueous extracts from the “strike anywhere” match
exemplar. A. Chromatogram of the extract from the unconsumed material.

 

 

 

 

 

mowing-304nm SAbumt 1-..- U 7 a . E_CD_1
4 l: I‘ F}
8.8—} g I;
3 5 13‘
7.54 .
l
l .
J l
“-34. ‘: l
3 l . l
5.07 l
r l
3.a~ l l l
. 1 ‘ l
l n 3 l
'~ ’ s *7 “ 3.
'. l .- s :2 l
Pm - 3 , l
1 3 Q l v E E K | '
i will K)“ g c /“ ‘ i
l v-l l \ u i l l
:L____JL»M'\._.1 \»~.~_./\ _L_./ \_b \__._-~_-_,._4
mirl'
‘1.U ‘V V 1 fir "fifi- --. r w v v . T #—1
0.0 5.0 10.0 15.0 20.0 25.0

Figure 2B. Chromatogram of the extract from the consumed material

18

.2983
:8 Loosom: 05 m0 880% 5.3 2H .< .780 ova 8a _.8o 03 3 $83 808883 05 .«o 888% on...
302 .8383 .988 :8 2: mo mfiahxu 38:3 2: 88m @2058.— mamhs me 860% 5.7m .m 9.53

93.0 83. oofl 95m gm 0.333..
. . OH”.
3.

cm

mm

mo

3

mm

mo
0 ca

19

3:3

3:3.

95. _

.0388 :8 gowns... 2: 8o 88% 8.8 2: .8... 2:5

033m

95m

9663.

ed”.

3

m».

.3.

S.

.3.

3.

20

100104111704011 School? EQQ_1__

 

 

 

 

 

. 1.518
4
1.
8 8-‘
J
J.
7.5 3
+
4‘
6.3;:
1
5.07.
4. 3
J 3 g
3.87 if 2 '7
4 I? . N 2‘ ‘
2 5': g o g g g 1
‘ -- 3 :2 fi :3 7 r
j I: q q ‘2 ’\x
.' o ' . '7 - .
1.3 ‘ k." r: E f
4 n l l g I ‘
‘ I! - l'. .33 A ,' .
. n t :‘I‘. C , ' I \ '
.L. . 'l 1“” ‘—"“’ \"-—/\.__._. J \ J \ j
T H
J .r .
'1.0 A Y 1 V V T ' Y r Y fl 7 v —-r-—"' —' r Y " v ‘ T " ' " ‘ '--- ~-mln‘
0.0 5.0 10.0 15.0 20.0 25.0

Figure 4. IC Chromatogram of the aqueous extract from the “School” control soil
sample. Note the absence of a chlorate peak.

21

 

 

 

. 10.0 .AN111704 #23. ‘. We-“ ,,Range_2.____-m__._-_" ___ Eco;
:“8 § 3. l
a i? I
8 8‘4 .; '5 1
1 3% 1 ’3 1
7 57 % Ii 1
9 | I
1 g ‘
3. * E i l
5.04 I ; =
j
< n :
38’. :5 'l : T‘
] é { = 1
2 5‘? '5 I I i
. “‘ 3 S O l
4. ‘ 5‘5. H E l l . ‘-
13—3 lg 3’ é .5 ~. ’ \
‘ Vt." I V E l , J
l M ". ‘ l l \
wag; Lkhwun 0.x,“ H -J \“mm___.
.101 . T '*—'r"“'*‘"'r* ,. _..-.-... .- r. . . . . -. . , . . . -min'
0.0 5.0 10.0 15.0 20.0

Figure 5. IC Chromatogram of the aqueous extract from the “Range” control soil
sample. Note the absence of a chlorate peak and the high concentration of sulfates.

22

 

 

Physical Examinations

Observations of all samples were recorded and compiled in Table 4. Physical
examination of the steel IEDS consisted of observations of the relative amount of
oxidation, or rust, present on the devices, as well as the color and nature of the interior
residue. Of the entire device set, only devices 86 and 863 displayed any fragmentation.
The residue material coating the interior of most of the devices consisted of a
combination of gray and red particles; however a few of the devices (S3, 84B, and 86B)
displayed only the gray particles. The residue material observed in the exemplars was a
dark grayish black in the black powder device and a lighter gray in the smokeless powder
device. Every sample in the set displayed some degree of oxidation, predominantly about
the end caps and threading (Figure 6). Intact match heads were identified in all of the
devices that employed whole heads as a filler. In 25% of the steel samples unconsumed
material was recovered for chemical analysis; while in 75% of the steel samples
consumed material was recovered.

Physical examination of the PVC devices consisted of observing the color and
nature of the residue, and grouping the fragments into the size classes detailed in the
methods section. The residue material observed on the IED interiors was a film of
orange-brown color which varied in shade from light to dark. The residue observed in
the exemplars was light brown for the black powder and gray for the smokeless powder.
In 71% of the PVC samples unconsumed material was recovered; while in 100% of the
PVC samples some consumed material was recovered for further analysis. In observing

the PVC IED fragments, it was noted that some of the fragments from the sample set had

23

20.0828 000300 0028.080 000 .00300 0.00.0
0an 0.0800 00 0800030000 00000.30 8.8.508. 00 :03 00 053 0.0800 800 0000002 000.0208 :0 00 005 .0 030,—.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

00.>00 :0 .050 00.00.“. >05 0:02 0:02 00
00.>00 :0 “0:0 00.00.". >05 0:0 000 E0020 0:02 00
00.>00 :0 .030 00.00.“. >05 0:0 000 E0020 E0020 000
00.>00 :0 00:”. 00.00.”. >05 E0020 0:02 00
00.>00 :0 “0:0 00.00.“. >05 0:0 000 0.0020 E0020 E0020 000
00.>00 :0 “0:0 00.00.“. >05 0:0 00m. 20.055 E0020 0:02 N0
00.>00 :0 «0:0 00.00.“. >05 0:0 00m. 20.9.30 E0020 0:02 0 F0
00.>00 :0 .030 00.00.“. >05 0:0 00m. 20.2.30 E0020 0:02 0
023020 0.00.22 >05 $2 (2 000.2080 0
023020 0.00.3.2 8520 E0... (2 $2 00500 0.00.0 0

023020 0800 E52000c05 0.9.2 E0020 0:02 0 00
023020 0800 85200005 0.9.5 E0020 E0020 0
022020 0800 85200005 E0020 0:02 000
022020 0800 85200055 E0020 E0020 00
023020 0800 E52000c05 E0020 E0020 000
028020 0800 E52000c05 E0020 E0020 00
022020 0800 25200005 E0020 E0020 000
022020 0800 E52000c05 E0020 E0020 0
023020 0800 85200005 E0020 E0020 000
023020 0800 85200005 E0020 E0020 «0
022020 0800 85200005 20.2.30 E0020 E0020 0N0 .
023020 0800 85200005 0.05% E0020 0:02 «0

00E. 00.0 85200005 20.0550 E0020 0:02 0 90

00E. 00.0 :52000c05 0.0.33 E0020 20.9.5 E0020 .0

2:. .050 00.00 030.000 00:50:00 00:50:85 0802 0.0800

 

 

24

 

 

 

 

 

 

 

. 00.2.80 0. 2...;
ES 20 6252090 00:0 02 >90 20: <82 <82 080on0 0
0800.5.
00.0 .00E08020 .0030 0.0... 0.00.0 :0305 <2 <2 L00500 0.00.0 0
00300 :0 .00”. 00.00.“. >05 0:0 000 0.055 E0020 0:02 0 0
E0020
0000... :0000>> .00300 :0 .000 00.00.". >05 0:0 000 0:02 E0020 >0
00E08020 .003". 0.0... 00.00.“. >05 E0020 0:02 000
00.:08020 .00300 :0 .000 00.00.". >05 0:0 00m. 0:02 0:02 00

 

 

 

 

 

 

25

 

Figure 6. Examples of the oxidation observed on the threads and caps of the steel
lEDs post-blast. The top pipe and cap are from sample $28, the bottom pipe and cap
are from sample S4.

26

some internal fractures. In the case of the smokeless powder and black powder
exemplars, many of the fragments displayed a large amount of internal fracturing (Figure
7). The results of the fragmentation analysis are presented in Figure 8, which shows the
percentage of fragments of each size type for each device in the PVC sample set as well
as the two exemplar samples. All of the samples except for P1 and P13 fragmented to
some degree, and only two samples (P6 and P6B) had fragments in the small size class
exceeding 50% of the total number of fragments. The rest of the samples were fairly
consistent in their fragmentation characteristics, displaying an even distribution of size
elements. The only exception to this was sample P2, in which a low number of fragments
were recovered for examination.
Microcrystal and Microchemical Examinations

All microchemical and microcrystal examinations were performed on the PLM,
and all data reported in Table 5. In the analysis of the PVC samples, 100% of the
unconsumed material samples displayed diamond shaped crystals of low order
birefringence in the water recrystalization examination. The consumed material samples
resulted in diamond shaped crystals of low order birefringence in 93% of the water
recrystalizations, with sample P6 giving inconclusive results. In 86% of the residue
samples low order diamond shaped crystals were formed during the water
recrystalization, with P5B giving inconclusive results and P6 giving negative results. All
material types from each sample in the PVC sample set formed hexagonal crystals in the
platinum chloride microchemical test. In the chloroform recrystalization examination,

80% of the unconsumed samples formed saw shaped crystals, 29% of the consumed

27

 

Figure 7. Examples of the fracturing observed in the fragments of the PVC IEDs
The fragment on the left is fi'om sample P3, the fragment on the right is from sam
PSmokeless. Note that while some minor fractures are observed in the fragment 1
the P3 sample IED .extensive fiacturing is observed in the fragment from the
PSmokeless IED.

28

 

 

 

o Q§
.33»:

 

 

Figure 8. Plot of the percentages of total fragments 1n each size grouping for all
unknown PVC samples, as well as the two PVC exemplars. Note that only samples
Pl, PlB, P6 and P68, display significant differences in size distributions from the

other unknown samples.

29

TI Type2 S%
‘I Type2 M%

a llT Tpe2 L%

 

Sample Name Material H20 PTCL Cl-iCL3
Type Recrystalizatlon Microchemical ‘ Recrystallization
P1
Unconsumed Positive Positive Positive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
P1 B
Consumed Positive Positive lnconclusive
Residue Positive Positive Positive (slight)
P2
Consumed Positive Positive Positive (slight)
Residue Positive Positive lnconclusive
P28
Unconsumed Positive Positive lnconclusive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
P3
Unconsumed Positive Positive Positive
Consumed Positive Positive Positive (slight)
Residue Positive Positive lnconclusive
P3B
Unconsumed Positive Positive Positive
Consumed Positive Positive Positive (slight)
Residue Positive Positive lnconclusive
P4
Unconsumed Positive Positive Positive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
P48
Unconsumed Positive Positive Positive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
P5
Unconsumed Positive Positive Positive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
P53
Unconsumed Positive Positive Positive
Consumed Positive Positive lnconclusive
Residue lnconclusive Positive lnconclusive
P6
Unconsumed Positive Positive lnconclusive
Consumed lnconclusive Positive . Positive
Residue Negative Positive lnconclusive

Table 5. Experimental results from the microcrystal and microchemical examinations
of the materials recovered from the sample IEDs.

3O

Sample Name Material H20 PTCL CHCL3
Type Recrystallzation Microchemical Recrystallzation
P68
Consumed Positive Positive Positive
Residue Positive Positive lnconclusive
P7
Unconsumed Positive Positive Positive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
P78
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
S1
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
S18
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
$2
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
$28
Unconsumed Positive Positive lnconclusive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
S3
Consumed Positive Positive lnconclusive
Residue Negative Positive lnconclusive
$38
Unconsumed Positive Positive lnconclusive
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
S4
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
S48
Residue Positive Positive lnconclusive
$6
Residue Positive Positive lnconclusive
$68
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
S7
Unconsumed lnconclusive Positive lnconclusive
Residue Positive Positive inconclusive
S78
Consumed Positive Positive lnconclusive
Residue Positive Positive lnconclusive
Table 5 (cont’d)

31

samples gave saw shaped crystals, and 7% of the residues formed saw shaped crystals.
All other results in the chloroform recrystalization were inconclusive, with the sample
displaying some crystal formation with no clearly discemable structure.

In the water recrystalization from the steel samples; 66% of the unconsumed
materials, 100% of the consumed materials, and 92% of the residues resulted in the
formation of diamond shaped crystals with low order birefiingence. All of the steel IEDs
had at least one type of material extracted from the device which resulted in the
formation of low order diamond shaped crystals by water recrystalization. All of the
material types from each of the steel samples formed hexagonal crystals in the platinum
chloride microchemical examination. None of the recovered materials for any of the
samples gave identifiable crystals in the chloroform recrystalization examination; all
results consisted of the formation of amorphous crystal groups.

Instrumental Examinations

All of the instrumental data were collected and compiled in Table 6. In the FTIR
of the PVC samples, 70% of the unconsumed material, 21% of the consumed material,
and 21% of the residues displayed absorbance peaks at 970 cm'1 and 940 cm"1 (Figure 9).
A chromatogram of the IC Standard solution is presented in Figure 10. Ion
chromatography of the unconsumed material detected chlorates, sulfates, and chlorides in
100% of the samples, and phosphates in 60% of the samples (Figure lla). The chlorate
peak was the strongest peak in all of the unconsumed material samples, with the
exception of the material from sample P6 where the sulfate peak was the strongest. In the

consumed materials recovered from the PVC IEDs, ion chromatography detected

32

.005. 0.0500 05 800.. 0205000 0.0.0208 05 00 000005085 U. 000 M50 05 800 02:02 00.002.000.00 .0 030,—.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

08802 3.2. 8.0 08.80 3.2. 00.8: 28.80 3.2. 00.0. 28.80 08802 0.6.8:
08082 3.2. 2.0. 08.80 3.2. :00. 28.80 3.2. 5.... 08.80 08022 025800
08022 3.2. ms“. 08.80 3.2. 8.. 08.80 3.2. 8.... 88.80 08022 85:88.5
000
08802 3.2. 00. F 5 08.80 3.2. :8. 08.80 3.2. 8.0. 08.80 08.80 89.0 80.80
8.80.5.2. 08.80 3.2. 8.8. 08.80 3.2. 00.80. 08.80 3.2. 8.. 08.80 08022 025800
3.3.
0.80.5.2. 28.80 3.2. 8.0. 08.80 3.2. 8... 08.80 8.8: 08.80 08.80 82:88.5
0...
08022 3.2. 2.0. 28.8.... 3.2. .08. 28.80 3.2. 0.3. 08.80 08022 08.80
3.2.
08022 3.2. 8.0.. 28.80 3.2. .0. 5. 98.80 8.8. 28.80 88.80 89.0 025800
3.2.
08082 3.2. 8. F. 88.80 3.2. 00.. 08.80 00.00. 88.80 08082 85:88.5
mun.
3.2. 3.00
08022 8.00.. 08.80 3.2. 00.3 0 08.8.. 5.0.. 08.80 08.80 89.0 08.8”.
08802 3.2. 8.8. 88.80 3.2. 8.80. 08.80 3.2. 80.. 08.80 $8.80 02588
«n.
8.882 3.2. 8.0. 08.8.. 3.2. 00.80. 08.80 3.2. 8.. 28.80 08802 80.80
0.80.5.2. 08.80 3.2. 008. 08.80 3.2. 8.80. 88.80 08022 08082 025800
0.0
3.2.
08082 03:. 08.8.. 3.2. 8.03.. 88.80 3.2. 0.... 08.80 08802 08.80
3.2.
08022 8.8 5 98.80 3.2. 2.02. 28.80 3.2. 8. c 28.80 28.80 89.0 025800
88...... .0 3.2.
08.80 3.2. 8.8. 08.80 3.2. 8.0. 08.80 8.80.. 88.80 28.8... 02588::
E
6.. 8.2080 6.. 8.0.30 6.. 8225 6.. 8.0.2.0 80.00.. «E .2205. 0......00

 

 

33

8.88. 0 0.000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.2. 00.0. 08.80 3.2. F00. 08.80 3.2. 00.000. 08.80 3.2. 00.. 08.80 080002 08.80
3.2. 00.0. 08.80 3.2. 00. F F. 08.80 3.2. 2.000. 08.80 3.2. 00.. 08.80 080002 000.088
080002 080.008. 08.80 3.2. 2.: 08.80 3.2. 00.0: 0.....80 08.8.0 00:588....
00
3.2. F0. 08.80 3.2. 00.0. 08.80 3.2. 00.FOF. 08.80 3.2. 00.0. 02.80 08.80 20.0 000.000
0.80.5.2. 08.80 8.0.0022. 08.80 3.2. FF. F0. 08.80 0000.008. 08.80 080002 000.088
000
080002 3.2. 00.0. 08.80 3.2. 00. F. 08.80 3.2. 2.. 08.80 080002 000.80
3.80.5.2. 08.80 3.2. 00.0. 08.80 3.2. 00.. 08.80 3.05 00.. 08.80 080002 000.088
0.80.5.2. 08.80 3.2. 00.0. 08.80 3.2. 00.. 08.80 3.2. 00.0. 08.80 080002 002088....
00
080002 3.2. 00.0. 08.80 3.2. F05. 08.80 3.2. 00.0. 0.....80 080002 08.80
3.80.0.0... 08.80 3.2. 2.0: 0.....80 3.2. 00.9 F. 08.80 3.2. 00.0. 08.80 080002 000.088
8.80.5.2. 08.80 3.2. 00F. 02.80 3.2. :0. 08.80 3.2. 2.00. 08.80 08.80 29.0 00:588....
000
080002 3.2. F00. 08.80 3.2. 00.0. 08.80 000.002.. 08.80 080002 08.80
0.80.5.2. 08.80 3.2. 00.00. 08.80 3.2. 00.000. 08.80 3.2. F0.F. 08.80 080002 000.088
080002 3.2. 00.0. 08.80 3.2. 00.0: 08.80 3.2. 00000. 08.80 08.80 005088....
00
6.80.5.2. 08.80 3.2. 00.0. 08.80 3.2. 00.00. 08.80 3.2. 2.: 08.80 080002 08.80
0:80.000. 08.80 3.2. 00.00. 08.80 3.2. 00.000. 02.80 0000.008. 0.....80 080002 00.5.88
0.80.0.2. 08.80 3.2. 00.0. 08.80 3.2. 00.0. 08.80 3.2. 00. F0. 08.80 08.80 0020885
000
8.80.5.2. 08.80 3.2. 00.0. 0.....80 3.2. 00.0. 08.80 3.2. 00.. 08.80 080002 08.000
080002 3.2. 2.0. 08.80 3.2. 00.00. 0.....80 080002 080002 005088
3.2. 00.0. 08.80 080.008. 08.80 3.2. 2.0. 08.80 200.58. 08.80 0.....80 000588....

 

 

 

 

 

 

 

 

 

vn.

 

34

.0008. 0 0.00.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

080002 3.2. 00.0: 08.80 3.2. E05 08.80 8.80.0.8. 08.80 080002 000.80
000
080002 3.2. 00.05 08.80 3.2. 00.000. 08.80 3.2. F0. 08.80 080002 08.000
3.2. 00.00. 08.80 3.2. 00.00. 08.80 3.2. 00.0000. 08.80 080002 080002 008088
00
080002 3.2. 00.00. 08.80 3.2. 00000. 08.80 8.80.5.2. 08.80 080002 08.000
080002 3.2. 00.0. 08.80 3.2. 0F.F0o0. 08.80 3.808.... 0.....80 080002 008088
8.80.0.0... 08.80 3.2. 00F. 08.80 3.2. 00.. 08.80 3.2. 00.000. 08.80 08.80 008088....
000
080002 3.2. 00.00. 08.80 3.2. E05 08.80 080002 080002 08.80
8.80.0.0... 08.80 3.2. 00.0. 08.80 3.2. 00.0000. 08.80 080002 080002 000.088
00
080002 3.2. 2.2. 08.80 800.88. 08.80 6.80.0.8. 02.80 080002 08.80
8.80.5.2. 08.80 3.2. 0F.0. 08.80 3.2. 00....F0. 08.80 080002 080002 000.088
080002 0.0.08.2. 08.80 3.2. 00.. 08.80 3.2. 00.0. 0.....80 080002 00:588....
000
080002 3.2. F002 08.80 3.2. 00.0000. 08.80 080002 080002 08.000
3.2. 00F. 08.80 3.2. 00.0. 08.80 3.2. 5002. 08.80 080002 080002 000.088
00
080002 3.2. 00.0: 08.80 3.2. 00.00. 08.80 080002 080002 08.80
$300.55.. 022000 3.9... owd. 022000 €05.50. 022090 02.0002 002.302 00:50:00
0 F0
080002 3.2. 00.00. 08.80 3.2. 00.00. 08.80 080002 080002 08.80
0.80.0.0... 08.80 3.2. 0200. 08.80 800.88. 08.80 080002 08.80 80:0 005088
F0
8.80.0.8. 08.80 3.2. 00.0. 08.80 3.2. 00.00. 08.80 3.2. 00.. 08.80 080002 000.000
080002 3.2. 00.05 08.80 3.2. 00.000. 08.80 3.2. 00F. 08.80 080002 000.088

 

 

 

 

 

 

 

 

mt”.

 

 

35

 

 

 

 

 

 

 

 

 

 

 

 

€008. 0 0.000
02.0002 3.0:. 00.0.. 02.000 3.0:. :00. 02.000 02.0002 02.0002 00200..
:04...
00.0. 02.000 3.0:. 00.0. 02.000 3.0:. 00. 0 00. 02.000 038.52. 02.000 02.0002 00050000
000
02.0002 3.0:. 00. 0 0. 02.000 3.0... 00.00. 02.000 3.0:. 0... 02.000 02.0002 000.000
02.0002 3.0... 00.. 02.000 3.0:. 00.. 02.000 0005.000. 02.000 02.000 20:0 00500085
00
3.0:. 00.. 02.000 3.0:. 00.00. 02.000 3.05 00.000: 02.000 3.06 00.. 02.000 02.0002 000.00..
03005:. 02.000 3.0... 0:. 02.000. 3.0:. 00.00. 02.000 02.0002 02.0002 0080008
000
02.0002 3.0... 00.0.. 02.000 3.0.: 00.0.. 02.000 0030055.. 02.000. 02.0002 002000
00

 

 

 

 

 

 

 

 

36

0.0.020 83000.00 5.? 00.0.8000 00.000. 780 ova 0:0 780 o3 2.0 0.080.020 05 020.00... 80.0.8 30.0.0... 00:50:80:
05 Eco .05 0.02 .3 0.0800 :8... 00.00600. 0090 3.0.0... 00.... 05 .0 080...... 0:00:00 0:. mo 0.00000 MEL. .0 0.33

3.30... coo. so: 83m cosm 3.3.x...

2.2.6.. 0..

32.0.02 32.30.23,. F.

.0...

£2.20; 00:50:80.: 3.

37

 

 

 

 

 

 

1o09.530978 #1 Anion "‘ A 7 500.1
408
8.8}
7.53.
.1
8.3?
.f n n
1 3 z: '3’. ..
507 ' 3 '7 N h '7!
1 a g §3 3. "t.
' v- F O
38" 3 I a. ' v.- E i
. ‘ 5 § § 8 =3 a
4 . .
i l ’ is i i r
25: 1‘ fl A B x r
.4 ,r ‘ r‘ 1 .l 8 ‘
I. ‘ ’ l y ‘l [l ‘
13‘ '1 ‘ ‘l f‘ l ‘ 1i ’ -
. ‘ . 1 ll l l
: E :l l 11»! ll /\ ; \ s
‘ a l ' K l‘ r" ' l \ f
;_-h“flL __J‘ \\#I K- _J V L \\‘.___~r_0/ \../ \. .
'10‘Jb—M '1 ' "' l v v I ‘ T Y Ym
0.0 5 0 10.0 15.0 20.0 25.0

Figure 10. IC chromatogram of the standard sample run in the Anion method.

Retention times of the 8 standard anions are displayed in minutes. Fluoride (3.4),
chloride (5.9), nitrite (7 .4), bromide (9.7), chlorate (10.4), nitrate (11.4), phosphate

(15.2), and sulfate (17.2).

38

chlorates in 86% of the samples, sulfates and chlorides in 100% of the samples, and
phosphates in 66% of the samples (Figure 11b). The chloride peak was the most
dominant peak in the consumed material samples, with the exception of sample P6 where
the sulfate peak was the strongest. In the PVC sample residues, chlorates, sulfates, and
chlorides were detected in 100% of the samples, and phosphates were detected in 36% of
the samples (figure 11c). The chloride peak was the strongest peak in the residue
samples, with the exception of samples P2, P5, and P6 where the sulfate peak was the
strongest.

In the FTIR analysis of the steel samples, 66% of the unconsumed material, 11%
of the consumed material, and none of the residue material displayed absorbance peaks at
970 cm"1 and 940 cm’I (Figure 12). Ion chromatography of the unconsumed materials
from the steel IEDs detected chlorates, chlorides, and sulfates in 100% of the samples,
and phosphates in 33% of the samples (Figure 13A). In the recovered consumed
materials from the steel IEDs chlorides and sulfates were detected in 100% of the
samples, chlorates were detected in 22% of the samples, and phosphates were detected in
89% of the samples (Figure 133). In the steel IED residue samples chlorides and sulfates
were detected in 100% of the samples, chlorates were detected in 58% of the samples,
and phosphates were detected in 8% of the samples (Figure 13C). Bromides were
detected in either the consumed materials or the residues recovered from 50% of the
samples, but were not detected in any of the unconsumed materials recovered. The
samples which indicated the presence of bromides were samples 81, S2, S2B, S33, S43,

and S6. In addition, an unidentified peak with a retention time of approximately 23

39

 

 

 

 

 

 

10 O_P§Btgf_7f_3 #1me __ g .. M P7 Whole ECD_1.:
jJS :
1
a 37"
7 5 i
i r
l l
631' a I
4 '1 l
. s: l
1 ' 1
5.0 3
l e !
2 !
4 g ,
3.8—4 :- ° 3
4 a, If! .
2.50 3 ?§ *1
; a 2 l l
< '3 3 5 : i
1 Y ‘
3 E .. l 1 \
a 3‘
= A. i (
, +—~—-———-—-—1 j\«} I\.._____.:[ K- -‘_,¥___,_J \_ __ /\ 4'
1 i.” .1
‘10. ' 1 if r r m r r r r r "Y—— .,_... fl -‘ '—"—'r *‘"‘r—' *1”—~—'r ******* min'
0 0 5.0 10.0 15 0 20.0 25 0

Figure 11. IC chromatograms of the aqueous extracts from the three material types
recovered fiom sample P7. The sulfate peak is unlabeled in Figure 11a, but
comparison with standard chromatograms indicates that the peak near 17 minutes is
sulfate. A. Chromatogram of the extract from the unconsumed material.

40

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

éEBtoPm 521 P7 B_gmt act) 1
10.0 is .__.
8.80] g
l
7 5 3‘
e 3« l
1 .. i
5.0 3
3 :5
3.3—: i
. 8 3
‘ '1
2 5— 5 3
5 '1 a g
.1...‘ , . 1 .0 a . l . . I . . .

0.0 5.0 10.0 15.0 20.0 25.0
Figure 113. Chromatogram of the extract fi-om the consumed material.
10.01538191733L ‘ _,_,._, -, _. FIRM $0.;

1

8.8—:
7.54
0.3-:
5.0:
3H S g

1 9 v:
25‘ v~ 8 3 ' '

l a 3 2 §. 2 fi

1 a - " : =

4 ' a ' _ g n

1.31 g g

1 c /\ / \

.

.10 ‘ . . , . . 1 . , I - :99;

0.0 5.0 10.0 15.0 20.0 25.0

Figure 11C. Chromatogram of the extract from the residue material.

41

8330.00 5.3 50.0.0030 00.000 780 ova 5:0 ~.50 03 050.00.00.05 05 $0305 .00..x0 3.0.0:. 50880000: 05

0.0.0 20

3:0 .05 0.02 .mmm 03800 80... 50.0.0000. 000». 3.0.0... 00.5 05 ..0 0.00.0.0 0:00:00 05 .0 050000 ME... .2 05w:—

0......»

so: _

com—

3va

:5...

0:20.02 2mm

3:202 50:50:90 mmm

3.0.02 52:30:30.5 mmm

3.25..

.7...

42

' 1o 00119330025 S38 Whole ECD _1

 

 

 

 

 

 

 

 

. #8 E; 1:
I g l
8.8: 3 i
1 55 i
7 53 5
6.3%
50‘ i
1 i
3.8% I i
1
l 3 -
2.5-4. 3 3 z; .
1 1'; ' 2 i
1.3 4‘ 5;- Y :3 g j
, 3 ~ ° \ a i
‘ l A ' 1
3...... ML__J\____A__ \k A /\ j
J ‘ g
'1 0"< Y #- 1! Y W a 7 —V— r r r v r 1 v I r f r r v “f r m"!
0.0 5.0 10.0 15.0 20.0 25.0

Figure 13. IC chromatograms of the aqueous extracts from the three material types
recovered from sample S3B. Note the small unlabeled peak near 15 minutes in the
unconsumed extract, indicating detection of phosphates. A. Chromatogram of the
extract from the unconsumed material.

43

333 Burnt ace 1

 

1 10.038130838 #27
.

8.8~

cm - 6.0"

Hr
w:
5.0%

3.01

  

mm- 11 '53
tum-16.001

 

-O|83
041.330

 

Ll M

QL

 

 

Y’fiirfiivfii’ffY

No.0 5.0 15.0 ' ' V ' 15.0 ' ' Y I 26.0 ' ‘ ' ' 25.(
Figure 13B. Chromatogram of the extract from the consumed material.

 

l 1001330838 '29 S38 Residue E00 1

l 8.8—:

7.51

0.3{

m 0-
‘l’ ?
fir cum - 10.817

 

(T)
M4“
3-4.141

 

" L
J N

V . . T . v . I Y . . . I . v
5.0 10.0 15.0 20.0 25.0

 

 

. 4.0

0

 

. .. lAAJ
o {
1

Figure 13C. Chromatogram of the extract from the residue.

44

 

minutes was observed in either the consumed material or residue recovered from 58% of
the steel devices, this peak was not observed in any of the recovered unconsumed
material (Figure 14). The samples with IC spectra displaying this peak were samples 81,

SIB, SZ, SZB, S3, 838, and S7.

45

 

 

10.0 s; 10333 «19 K S28 ReSIdue<__ _ 7 W 4__7A_ ecp‘r
l“ 3'. 31 ‘
1‘ "7 :2:
8.8 " “
j 3
3
C
7.5
4 .
637 1
f i
5.01 1
4
3 8%
2 5 2 ". l n '
~ § '- l 8 , S
l l in 1 9 l 5
1 3 1 5 . ll , .\ n l ';
7 ll 3? ' Fl
, ‘3. \\ , p
:__,n_~l \\ f2, K H_ \\z \_\ A ‘ .. v“ 1’ \\¥ .__a___m.// \_ A
-10. , , , . -- Y ..- . .. T .. _ .ir.,n.-... .... .- 71‘ ml".
0.0 50 100 150 200 250

Figure 14. IC chromatogram of the aqueous extract from the residue of sample PZB.
The peak at 9.6 minutes was identified as bromide by comparison with a standard
spectrum. The peak near 23 minutes was unidentifiable by comparison with a
standard spectrum.

46

DISCUSSION

Physical Examinations

The presence of rust on the steel pipes is most likely due to chemical interactions
between the surface of the pipes and the potassium chlorate. As potassium chlorate is a
strong oxidizer, it is likely that the residual potassium chlorate from the explosive
material facilitated oxidation of the pipes during the time period between the detonation
of the devices and their subsequent analyses four months later. This is of significance, as
the oxidation process can consume the potassium chlorate, presenting difficulties in the
analysis of devices.

In examining the residue on the devices, it was noted that 75% of the steel and
100% of the PVC devices displayed residues with a reddish or orange coloring. This is
most likely due to the red coloring of the material fiom the match heads, as it was not
observed in the black powder or smokeless powder exemplars (Figure 15). The brown
coloring was present only in the PVC devices and may be due to one or both of the
following possibilities. Due to the fact that most of the PVC IEDs fragmented to some
extent, the interior surfaces of the devices were exposed to the soil that the samples were
transported in, and because of this soil material may have become ingrained on the
interior surfaces with the residue material. The other possibility is that the darkening
observed in the PVC samples is due to scorching of the plastics during the deflagration of
the devices. This seems likely as PVC melts at 175 degrees C, while the initial ignition
temperature of a match is 260 degrees C and temperatures of match flames may reach up
to 2500 degrees C. It is most likely that the brown coloring is a result of both of these

factors. In addition to the coloring differences between the steel and PVC samples, the

47

 

Figure 15. Photograph displaying the residue color from samples P4 (left) and
PBlackPowder (right). Note the red-orange color of the P4 sample and the
gray color of the PBlackPowder sample.

48

natures of the residues differed. The residues in the steel devices appeared particulate in
nature, while the residues from the PVC devices had a more film-like consistency with
some particulates embedded in the film. The fihn-like residue of the PVC [EDS can most
likely be attributed to melting of the PVC surface during deflagration, allowing the
particles from the explosive load to become embedded in the surface before the PVC
resolidified.

The presence of unconsumed and consumed material is of particular importance
in the analysis of these IEDs. In addition to the benefit of having load material to analyze
for chemical content, the physical appearance of the material is useful in directing
examinations. In all of the samples that utilized whole match heads, some match heads
were found either within the device or scattered in the blast radius with the fragments of
the IED during the collection phase. Most of the heads had unconsumed material on
them, with only device P1 yielding a whole head with unconsumed material on it (Figure
16). Device S7 did not contain any whole heads with material on them, however whole
heads without material were identifiable in the device. This is significant, as
investigators can expect to find whole heads if a “cut” method was used in the
construction of IEDs, which will in turn be helpful in ultimately characterizing the
explosive load used in the device.

The coloring of the match head material makes it easily differentiable from most
low explosive mixtures. Some smokeless powders contain red coloring, including the
Red Dot powder used in the smokeless powder exemplars. In comparing the
morphologies of the Red Dot smokeless powder to that of the unconsumed material,

differences were observed (Figure 17). The Red Dot smokeless powder had crushed ball

49

 

Figure 16. Photomicrograph of recovered intact match heads from various devices.

50

 

Figure 17. Photomicrograph of chipped match head material (left) and a flake of Red
Dot commercial smokeless powder (right). Note the differences in shape, color, and
luster in the two samples. '

51

morphology, while the match head chips had more irregular shapes and edges. The
match head material was much more granular in appearance and had a'bright red color,
while the Red Dot powder was smoother in surface texture with a more lustrous coating
and a dull maroon-red color. Based on morphology, it was possible to differentiate the
match head material fiom the Red Dot smokeless powder, and it may be possible to
differentiate the match head material from other colored pyrotechnic mixtures and
commercial powders. A point to note however is that many commercial matches are
produced with different colorings, which may either make it easier or more difficult to
differentiate them from other commercial low explosives.

The fragmentation analysis of the PVC IEDs gave some suggestive information
which may be useful in characterizing the method used to prepare the explosive load in a
match head based device. The P1 and P13 devices employed the cut wooden “safety”
matches, and were the only devices of the set to display no fragmentation. This seemed
consistent with the hypothesis that the wood from the match body inside the heads would
decrease the overall brisance of the load. Conversely, the only steel IEDs that
fragmented (S6 and 86B) employed ground “strike anywhere” loads, which seems to
indicate that this preparation yields the explosive load with the greatest brisance. The
fragmentation analysis seems to support this conclusion, as the two PVC devices
employing ground “strike anywhere” match material (P6 and P63) were the only PVC
samples that had more than 50% of the fragments collected in the small size class. The
fragmentation grouping of the P6 and P63 devices were similar to that of the exemplars
(smokeless powder and black powder), being predominantly small fragments, suggesting

again that the ground “strike anywhere” material is the explosive load with the greatest

52

brisance. With the exception of the weakest devices (P1 and PlB) and the strongest
devices (P6 and P6B), no clear differentiation between preparations can be made based
on fragment size groupings. All of the remaining samples had fairly consistent size
groupings with no discemable pattern. The only device, aside from the aforementioned
exceptions, that was differentiable was sample P2, which had only 4% of the fi'agments in
the small size class. This may not be due to the observed brisance of the device and is
most likely due to the fact that only 23 fragments were recovered from sample P2. It is
probable that many of the fragments were lost in the collection phase due to an
incomplete collection of fragments, and it is more likely that the fragments that were not
recovered would have fallen into the small size class, which would account for the low
percentage of fiagments in that size grouping. While there seems to be no clear
differentiation between the intermediate explosive preparations by fiagment sizes alone,
the total sample population is not large enough to be considered representative. With
such a restricted sample size, it may not be possible to see smaller differences between
the various preparation types.
Microcrystal and Microchemical Examinations

The water recrystalization examination was an effective method for the
characterization of potassium chlorate in the samples. No significant crystal formations
were observed in the School soil control samples, and while the Range soil control
samples displayed a multitude of various crystal structures, no low order diamond shapes
indicative of potassium chlorate were observed. Based on these findings, the soil could
be excluded as a possible source of the crystals observed in the analyses of the sample

materials. In both the PVC and steel IED samples every device displayed a positive

53

response to the water recrystalization with at least one form of recovered material; the
unconsumed material, the consumed material, or the extracted residue. Of the PVC
samples, only P5B and P6 gave non-positive responses in the water recrystalization. The
consumed material recovered from sample P6 gave inconclusive results, while the residue
from sample P6 yielded no appreciable crystals. Sample P6 was found to have a large '
amount of soil covering the device surfaces during the physical examination, which may
explain the non-positive results observed with the materials recovered from that device.
It is possible that some substances in the soil itself interfered with the recrystalization, or
that the presence of the soil merely decreased the amount of potassium chlorate that was
extracted in these two material types which then led to the non-positive results. The
extracted residue from PSB resulted in an inconclusive response to the water
recrystalization, and this is most likely due to a low concentration of potassium chlorate
in the residue that was extracted. The unconsumed material from sample S7 gave
inconclusive results and the residue extracted from sample SB gave negative results, both
of which may be due to low amounts of potassium chlorate in the samples. As was
discussed in the physical examination section, potassium chlorate is a strong oxidizer and
it is possible that the trace amounts originally in these samples diminished over time as
the potassium chlorate reacted with the pipe surface. In addition, the presence of iron
oxide could have caused interference in the recrystalization of these samples, resulting in
the non-positive responses.

Slight positive responses were observed in some of the soil control samples
during the platinum chloride microchemical examinations. This is most likely due to the

presence of some small amounts of potassium or potassium salts in the soil samples, as

54

the hexagonal shapes are presumptive of potassium. In a negative control of the
deionized (NERL), water no crystal formations were observed. Based on this, it is
unlikely that the deionized (NERL) water used in the extractions or a contaminant in the
platinum chloride reagent were contributing factors to the results observed in the soil
control examinations. In the School soil samples, the predominant structures observed
were diamond shapes, with a few small scattered hexagons present, while in the Range
samples the predominant structures observed were burrs of needles and curved needles,
with only a few hexagons observed in 60% of the samples. In comparison, all material
types from both the PVC and steel IEDs gave strong positive responses to the platinum
chloride examinations. The predominant crystal structures observed were hexagons and
large amorphous angular crystals. The hexagons were observed in greater size and
abundance for the IED samples than in the soil control samples, which suggests that the
positive response is a result of interaction between the platinum chloride and the
potassium present in the samples and not due merely to contamination from the soil. The
larger amorphous crystals are most likely the result of multiple hexagon complexes
combining to form larger structures, which may occur in very concentrated samples.
The background soil controls resulted in no appreciable crystal formation in the
chloroform recrystalization examinations, indicating an absence of elemental sulfur in the
background of the samples. The PVC IED samples displayed the formation of saw
shaped crystals in 86% of the devices, with only samples P2B and P7B yielding no
conclusive results in any material examined. In 80% of the unconsumed material
samples a positive response was observed, while in the consumed materials only 29% of

the samples gave a positive response and in the residues only one sample gave a positive

55

response. This is most likely due to the consumption of the elemental sulfur during the
deflagration process. This is supported by the results from the IC examination of
samples, in which the unconsumed materials contain low concentrations of sulfates,
while the consumed materials and the residues display increased concentrations of
sulfates. In addition, in the reference standards of consumed match heads only the paper
“safety” matches resulted in a positive response to the chloroform recrystalization, while
the wooden “safety” match and the “strike anywhere” match samples both gave
inconclusive results. While it is possible to obtain positive results from the chloroform
recrystalization of consumed and residue materials, it should not be expected, and also
should not be grounds for the exclusion of match head material as a possible explosive
load in a recovered IED. In the steel samples, all of the materials examined resulted in
the formation of amorphous crystal groups in the chloroform recrystalization, leading to
inconclusive results. It is uncertain why the unconsumed materials from the steel devices
did not yield a positive result. In all of the materials examined by chloroform
recrystalization, some crystal formation was observed even though structures were not
identifiable in each sample. It is possible that due to the consumption of sulfur during
deflagration the concentrations of sulfur in the extracts were too low to allow for
complete crystal formation in most of the consumed materials and residues. It is also
possible that secondary reaction products, such as the iron oxide, created interference
which prevented the formation of characteristic crystals. In addition, the amounts of
unconsumed materials that were recovered from the steel IEDs were much smaller than

those of the recovered unconsumed materials from the PVC IEDs. Because of this, it is

56

possible that the concentrations of elemental sulfur in the small amounts of unconsumed
materials from the steel IEDs was too low to give appreciable crystal formation.
Instrumental Examinations

The absence of absorption peaks at 970 cm'1 and 940 cm‘1 in the soil control
samples confirms the absence of potassium chlorate to any appreciable amount in the
background of the IED samples. The FTIR analyses of the extractions from the PVC
sample materials proved effective, giving confirmation of the presence of potassium
chlorate in 71% of the samples. Identification of potassium chlorate was much more
effective in the unconsumed materials (70%) than in the consumed materials (21%) or the
residues (21%). This was to be expected as most of the potassium chlorate would have
been consumed in the deflagration process, making it more difficult to detect in the
consumed and residue materials. The steel sample extractions had a significantly lower
success rate, with only 25% of the samples confirming the presence of potassium chlorate
by FTIR. The unconsumed materials had a much greater success rate (66%) than the
consumed materials (11%) or the residues (0%), which is consistent with the observations
made in the PVC sample material extractions. While the unconsumed materials from the
PVC and steel devices had comparable success rates, the success rates for the consumed
materials and the residues in the steel devices were significantly lower than those
observed from the PVC devices. This may be due to interactions between the potassium
chlorate and the surface of the pipes. If significant amounts of the potassium chlorate
were consumed while oxidizing the steel pipe surfaces, there may not have been enough
remaining in the extractions to give conclusive results by FTIR. Because this could be a

significant factor in the characterization of the potassium chlorate, it should be noted that

57

in the case of steel IEDs rapid analysis may be necessary to avoid the loss of valuable
probative information.

Ion chromatography of the soil control samples failed to detect the presence of
any chlorates, indicating that the chlorate results obtained in the samples were in fact due
to the presence of chlorates in the match head material. Chlorates were detected in 100%
of the PVC IED samples, and were detected in 67% of the steel IED samples. The high
success rates observed with this technique may be attributed to that fact that IC is a
separatory technique, which would allow for the isolation of the chlorates from other
substances in the sample which may have led to interference in other examinations. The
absence of chlorates in the consumed material samples from some of the devices is not
unexpected, as IC analysis of the consumed wooden “safety” match head exemplar did
not detect chlorates. It is possible that in the samples recovered from these devices, the
consumption of the potassitun chlorate went to completion to such a degree as to leave
concentrations of chlorates that were below the limits of detection for the system. In the
steel samples, it is possible that success rates lower than those observed in the PVC
samples was due to the consumption of potassium chlorate via the oxidation of the steel
pipes, as discussed in the FT IR results. For both the PVC and steel sample sets, the
chlorate peak was the most abundant peak in the unconsumed material samples; which
can be expected as potassium chlorate is the predominant water soluble ionic species in
the unconsumed match material, as observed in the match head exemplars. The only
exception to this was the unconsumed material from sample P6, in which the sulfate peak

was dominant. It is probable that this was due to the unusually large amount of soil

58

present on the surfaces of the device, which could have imparted greater amounts of
sulfates to the sample during the aqueous extraction.

In the consumed material and residue samples the chloride peak was the dominant
peak, with the exception of samples S3, P6, P5 and P2. In both the consumed material
and the residue material fiom sample P6, sulfates were detected as the most abundant
anion which is most likely due to contributions from the soil on the sample. The residue
from sample P2 had sulfates as the most abundant peak; this is most likely due to
contamination from the range soil, which displayed extremely high concentrations of
sulfates. It is unclear as to why in the IC analyses of the residue materials from samples
P5 and S3 sulfates were the most abundant ion. It is possible that the increased sulfate
concentrations could be due to soil contamination, or it is possible that there was a lower
than average amount of chlorides in the residues from these samples. While chlorides
were detected in the background soil samples, the amounts detected in the IED samples
was of a much greater concentration than that of the soil samples, which seems to
indicate that at least some of the contribution to the chloride anion peaks was from the
match head material in the IEDs. The chlorides detected were most likely formed as a
reaction product from the deflagration of the explosive loads, which consumed the
potassium chlorate converting them to more stable chlorides. Sulfates were also detected
in significant amounts in the consumed material and residue samples from the IEDs.
However, the amounts of sulfates detected were comparable to the amounts detected in
the soil control samples. It is possible that sulfates were formed as reaction products
from the deflagration of the match head material, but due to the comparable amounts of

sulfates in the soil control samples it is not clear if any of the sulfates detected were

59

definitely from the sample materials analyzed. Also, due to the design. of the experiment,
true quantitative comparison between samples and controls is not possible. Because of
these factors, it does not appear that the detection of trace amounts of sulfates can be used
as a means to include or exclude match heads as a possible source for the explosive load
in an IED, especially in instances where the IED is recovered from soil material.

Phosphates were detected to some degree in all of the match head exemplars, both
unconsumed and consumed. Phosphates were detected in at least one of the materials
recovered from the IEDs in 79% of the PVC devices and in 75% of the steel devices.
There seems to be no correlation between the type of match head used in the construction
of the device (“strike anywhere” vs. “safety”) and the detection of phosphates by IC. It
was originally believed that the phosphorous sesquisulfide present in the “strike
anywhere” matches would lead to detectable differences in the concentrations of
phosphates between “safety” devices and “strike anywhere” devices, particularly in the
consumed materials and the residues, but this does not appear to be the case. It is notable
however that phosphates were detected in a miniscule amount in only one of the School
soil samples, and thus the detection of phosphates in the IED samples seems resultant of
contributions from the match head material used as the explosive load. Based on this, it
seems that the detection of phosphates by IC may be suggestive of a match head based
IED, though the absence of phosphates does not necessarily exclude match heads as a
possible explosive load.

Aside fi'om differing success rates, there were some observable differences
between the ion chromatographs of the steel and PVC IEDs. The detection of bromides

as well as the detection of an unidentified peak at 23 minutes was observed only in steel

60

IED samples. In addition, the detection of these two peaks occurred only in the
consumed material samples and the residues recovered from some of the steel devices.
While the peak near 10 minutes in the unconsumed material sample fi'om S7 is labeled as
bromide, comparison with the anion standard suggests that the peak is actually chlorate,
and the mislabeling occurred due to misinterpretation by the software. As neither the
bromide peak nor the peak at 23 minutes appear in any of the soil control samples, it
seems most likely that the anions being detected are from the IEDs and are not due to
contaminants fi'om the environment. Because these peaks only occur in the consumed
material and residues, and not the unconsumed material, they are most likely due to
reaction products from the deflagration of the match head material. The IC analysis of
the paper “safety” consumed material detected bromide, so it is possible that some
component of the match head material forms bromides on deflagration. It is unclear as to
whether these bromides are formed in small amounts and only occasionally form to such
a degree that they are detectable by 1C, or if they are due to some contaminant imparted
to the match head material during manufacturing. ‘It is possible that the peak near 23
minutes was only observed in the steel samples because the anions formed are the results
of interactions between a component of the sample material and the steel devices during
deflagration. The presence of oxidation on the steel devices indicates that some
interaction is occurring, and it is unclear as to the contribution that this secondary

reaction has on the formation of water soluble organic species.

61

CONCLUSIONS
The analytical scheme presented is a rapid and effective method of characterizing match
heads as the explosive load used in IEDs. The combination of analytical techniques
creates a class of physical and chemical characteristics that can exclude most common
low explosives as possible materials used in the construction of such devices. By
employing this system of analysis, 100% of the PVC IEDs and 75% of the steel IEDS
were characterized sufficiently to identify the explosive load according to TWGFEX
guidelines. Physical examination of the recovered device is effective in narrowing the
range of focus for the chemical analysis of [ED components. In the case of devices
constructed using cut match heads it is expected that some heads would be recovered
from a blast site, giving a clear indication of the type of material and preparation used.
Particularly in the case of PVC devices the recovery of unconsumed materials can be
expected, and a physical examination can be used to exclude most commercial low
explosives and pyrotechnic mixtures as possible sources based on morphology alone.
The coloration and appearance of residue material on the fragments may also suggest to
the analyst that the device in question was a match head based IED. The high success
rate observed in the water recrystalization analyses for all of the recovered material types
allows for a rapid and inexpensive chemical analysis that can detect the presence of
potassium chlorate; which is an uncommon low explosive oxidizer particularly in
commercial preparations produced within the United States. The greatest drawback to
the microchemical and microcrystal examinations is that they rely on the subjective
interpretation of the analyst. Analysts uncomfortable or unfamiliar with PLM methods

may not receive confident results with the microscopic examinations that were performed

62

in this study. Specialized training course offered through various agencies such as the
McCrone Institute of professional organizations may provide analysts with more in depth
instruction in these methods. The detection of elemental sulfur by chloroform
recrystalization was fairly effective in the PVC samples, and successful identification of
sulfur can be a simple means for the exclusion of commercial smokeless powders as
possible explosive loads, as they do not contain elemental sulfur in their formulations.

FTIR is an effective means of identifying potassium chlorate particularly in
unconsumed material, and could be an effective method of analysis for analysts
inexperienced with PLM examinations. However, due to the use of pressed KBr pellets
in the scheme for the FT IR analyses some amount of sample was lost, and in cases with
limited sample material this loss may not be acceptable. It should be noted that every
sample material which detected potassium chlorate by FTIR also detected potassium
chlorate in the PLM examinations, potassium in the microchemical examination, and
chlorates in IC. In light of these observations, FTIR appears to be the least effective
method of characterizing potassium chlorate from match head based IEDs, and may not
be necessary if the other three methods are successful. IC has shown to be the most
effective instrumental method used in this study for the analysis of match head based
IEDs. The separatory nature of the system can accommodate for complex sample
mixtures, allowing the isolation and detection of desired anions. In addition, the low
limits of detection for the system allowed for the detection of chlorates in samples where
FTIR was unable to clearly identify potassium chlorate, which was particularly useful in
the examination of the consumed materials and residues. The success rate of the

detection of chlorates by IC is exceptional, and on par with the success rates of the

63

nricrochenrical and microcrystal examinations. In addition, the high concentrations of
chlorides detected in the consumed materials and residues seems suggestive of the
consumption of chlorates during the deflagration process, which may be significant in the
cases where the concentration of chlorates is at an undetectable level (such as is in
samples P13 and P4). While it is possible that the detection of sulfates could be
suggestive of a match head based IED, the extent of contamination from the soil at the
detonation sites cannot adequately be accounted for in this study and as such no
conclusions based on sulfate detection by IC can be made regarding the nature of the
device. The detection of phosphates, while less successful than the detection of chlorates
or chlorides, could be suggestive of a match head based device. However, their absence
cannot be used as a means for the exclusion of match heads as having been used in an
IED as they were not detected in all of the reference match head samples. The major
drawback to analysis by IC is that only the anions of a sample are detected. While
chlorates were detected in all of the samples, the IC methods employed were incapable of
detecting the cations in the samples. Thus, while it is possible to identify the presence of
chlorates, IC is incapable of characterizing potassium chlorate specifically. Thus, it is
important to employ complementary techniques such as PLM examinations or SEM-
EDS.

Despite the inability to differentiate “strike anywhere” match based IEDs from
“safety” match based IEDs, this study has demonstrated that the analytical scheme
employed is effective in characterizing commercial match heads as the explosive load
used in IEDs. The combination of morphological examinations, instrumental techniques

and microscopic analyses has been shown to be effective in identifying characteristics

64

that can be used to include commercial match heads as the possible explosive load, while
simultaneously eliminating other common low explosives. Most of the techniques that
were used in this study are commonly employed by forensic analysts, so the
implementation of this scheme presents no additional costs to crime laboratories. Most
importantly, the analytical scheme presented in this study is a rapid and effective method

for analyzing match head based IEDs.

65

FUTURE WORK

This study serves as a preliminary evaluation of methods that may be employed
for the analysis of match head based IEDs. More in depth examinations of various
aspects of this study would serve to strengthen the conclusions drawn herein. A larger
sample population for each of the device construction types would allow for a more
statistically significant population, which would in turn allow for more meaningful data
to be obtained from fragmentation pattern analyses. Also, a more effective sample
collection method should be employed to ensure that all fragrrrents would be collected for
size grouping, as some of the smaller fi'agments may have been lost during recovery in
this study. Another area of this study that warrants further investigation is the detection
of sulfates by IC. A method of sample collection would have to be employed that would
eliminate possible background contamination, as deflagration in soil has been shown to
be a likely source of contamination. A comparative study with other chlorate based
explosive mixtures should also be performed. Such a study would strengthen the class
characteristics identified in this study as being indicative of match head based IEDs.
Finally, other methods of detection should be researched, as no method employed in this
study was able to chemically differentiate samples constructed using “strike anywhere”
matches fiom samples employing “safety matches”. Such a differentiation would create
smaller class sizes for match head based IEDs and thus help to eliminate Type II errors in

casework.

66

REFERENCES

Glattstein, B., Landau, E., and Zeichner, A., Identification of Match Head Residues in
Post-Explosion Debris, Journal of Forensic Sciences, 1991, Volume 36, #5.

Miller, F. A., and Wilkins, C. H., Infrared Spectra and Characteristic Frequencies of
Inorganic Ions, Analytical Chemistry, 1952, Volume 24, #8, 317-358.

Hopen, T. J., and Kilbourn, J. H., Characterization and Identification of Water Soluble
Explosives, The Microscope, 1985, Volume 33, #1, 1-22.

Washington, W. D., and Midkiff, C. R., Systematic Approach to the Detection of
Explosive Residues. I. Basic Techniques, Journal of the Association of Oflicial
Analytical Chemists, 1972, Volume 55, 265-276.

Beveridge, A.D., Payton, S.F., Audette, R.J., Lambertus, A.J., and Shaddick, R.C.,
Systematic Analysis of Explosive Residues, Journal of Forensic Sciences, 1975, Volume
20, #3, 431-453.

Manon, J .J ., Explosives: their classification and characteristics, Engineering and Mining
Journal, 1976, October, 81-85.

“Recommended Guidelines for Forensic Identification of Intact Explosives”, TWGFEX

Laboram Eglosion Group Standards and Protocols Committee,
http://ncfs.ucf.edu/twgfex/Guide%2Ofor°/020identificati_on%2Oof"/o20iLt_act%ZOexplosives
MI, 1999.

“Training Guide for Explosive Analysis Training”, TWGFEX,
http://ncfs.ucf.edu/twgfex/ExplosiveAnalvstTrainingGuide.pdf, 1999.

67

illflllllllflllllflflljljll111111

 

 

4".‘—‘.‘_— -—._.____.