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01037c1Ale I
/oW1bW ?
THE ANALYSIS OF FIRE DEBRIS USING NUCLEAR
MAGNETIC RESONANCE SPECTROSCOPY
THESIS
Presented to the Graduate Council of the
North Texas State University in Partial
Fulfillment of the Requirements
For the Degree of
MASTER OF SCIENCE
By
Kenneth L. Bryce, B.S.
Denton, Texas
August, 1981
Bryce, Kenneth L., The Analysis of Fire Debris Using
Nuclear Magnetic Resonance Spectroscopy. Master of
Science (Chemistry), August, 1981, 49 pp., 4 tables,
bibliography, 26 titles.
This paper describes a new technique for analyzing
fire debris using nuclear magnetic resonance (NMR)
spectroscopy. Petroleum distillates, which are commonly
used accelerants, were weathered, burned, and steam-
distilled. These, as well as virgin samples of the
accelerants, were analyzed by gas chromatography and
nuclear magnetic resonance spectroscopy. In addition,
solvent studies and detectibility limit studies were
conducted. The use of NMR is described as a valuable
adjunct to the existing methods of analysis.
TABLE OF CONTENTS
PageLIST OF TABLES . . . . . . . . . . . . . . . . . . iv
LIST OF ILLUSTRATIONS . . . . . . . . . . . . . . . v
Chapter
I. INTRODUCTION . . . . . . . . . . . . . . . 1
The ProblemMethods of Analysis--Past and PresentScope of the Research
II. MATERIALS AND METHODS . . . . . . . . . . 6
Choice of Accelerants to be StudiedPreparation of Weathered AccelerantsPreparation of Burned and Steam-
Distilled AccelerantsAnalysisSolvent StudyDetectability Limit Study
III. RESULTS AND DISCUSSION . . . . . . . . . . 12
Steam Distillation of AccelerantsInterpretation of SpectraSolvent StudyDetectability Limit StudyCase StudiesMerits and LimitationsScheme of Analysis
BIBLIOGRAPHY . . . . . . ... . . . . . . . . . . . 47
iii
LIST OF TABLES
Table Page
I. Suspicious and Incendiary Fires in theUnited States.. ..... . . . . . . . 1
II. Frequency of Petroleum DistillatesRecovered From Fire Debris . . . . . . 6
III. Accelerants Studies . . . . . . . . . . . 7
IV. Distillates Collected by SteamD ist il11at io n . . . . . . . . . . . . . 12
iv
LIST OF ILLUSTRATIONS
Figure Page
1. Steam Distillation Apparatus . . . . . . . 9
2. NMR Spectra of Aromatic PetroleumDistillates and Texaco UnleadedGasol ine . . . . . . . . . . . . . . . . 13
3. NMR Spectra of Texaco Unleaded Gasoline . . 15
4. NMR Spectra of Shell Unleaded Gasoline . . 16
5. NMR Spectra of Varsol . . . . . . . . . . . 17
6. NMR Spectra of Tru-Test Paint Thinner . . . 18
7. NMR Spectra of Sunnyside Kerosine . . . . . 19
8. NMR Spectra of Gulf Charcoal LighterFluid . . . . . . . . . . . . . . . . . 20
9. NMR Spectra of Conoco Diesel . . . . . . . 21
10. NMR Spectra of Texaco Regular Gasoline . . 22
11. NMR Spectra of Shell Regular Gasoline . . . 23
12. NMR Spectra of Exxon Unleaded Gasoline . . 24
13. NMR Spectra of Exxon Regular Gasoline . . . 25
14. NMR Spectra of Painters Naphtha . . . . . . 26
15. Gas Chromatograms of Texaco UnleadedGasoline . . . . . . . . . . . . . . . . 28
16. Gas Chromatograms of Texaco RegularGasoline . . . . . . . . . . . . . . . . 29
17. Gas Chromatograms of Exxon UnleadedGasoline . . . . . . . . . . . . . . . . .30
18. Gas Chromatograms of Exxon RegularGasoline . . . . . . . . . . . . . . . . 31
V
Figure Page
19. Gas Chromatograms of Shell UnleadedGasoline . . . . . . . . . . . . . . . . 32
20. Gas Chromatograms of Shell RegularGasoline . . . . . . . . . . . . . . . . 33
21. Gas Chromatograms of Varsol . . . . . . . . 34
22. Gas Chromatograms of Tru-Test PaintThinner . . . . . . . . . . . . . . . . 35
23. Gas Chromatograms of Gulf Charcoa.lLighter Fluid . . . . . . . . . . . . . 36
24. Gas Chromatograms of Sunnyside Kerosine . . 37
25. NMR Spectra of.Texaco Unleaded Gasoline--Detectibility Limit . . . . . . . . . . 39
26. NMR Spectra of Gasolines . . . . . . . . . 40
27. NMR Spectra of Case Studies . . . . . . . . 41
28. Existing Flow Chart of Fire DebrisAnalysis . . . . . . . . . . . . . . . . 44
29. Flow Chart of Fire Debris Analysis . . . . 45
vi
CHAPTER I
INTRODUCTION
The Problem
In today's society, arson is one of the most
significant criminal problems (6). "Nobody is really
unconcerned about arson: they all agree that it is a
problem that needs work. They just believe somebody else
is working on it" (11). The crime of arson, often
referred to as "the crime of the century" and "America's
most malignant crime," is rapidly increasing in frequency
and monetary loss, as revealed by statistics compiled by
Carter (3) and detailed in Table I.
Table I
SUSPICIOUS AND INCENDIARY FIRES IN THEUNITED STATES
Number of Fires
177,000144,10094,30072,10056,30044,10033,90030,90021, 40020,30015,0009,6007,5005.600
Monetary Loss
1,159,000,000633,900,000320,000,000233,000,000179,000,000141,700,00074,000,00055,000,00038,400,00027,730,00026,730,00027,100,00022,000,00016,100,000
1
Year ($)
19771975197319711969196719651963196119591957195519531951
2
In keeping with the increase in suspicious fires, the
number of suspected arson cases submitted to crime
laboratories has also dramatically increased. Even so,
only a small amount of research and development has been
expended in the arson problem, its investigative
techniques, and related equipment (12).
Methods of Analysis--Past and Present
Before 1952, attempts to identify petroleum
distillates from fire debris were limited to observable
physical properties such as refractive index, boiling
range, flashpoint, and density (4). Infrared spectroscopy
(IR) was also used (4, 18). In 1952, the development of
gas-liquid chromatography (GLC) gave the analyst a
powerful analytical procedure to use in the separation and
identification of petroleum distillates (4).
Stone (18) related the history of gas chromatography
(GC) analysis as it was utilized by the fire debris
analyst. The use of GLC was first documented by Midkiff
and Washington in 1971 (15). In 1975, Cain reported the
use of capillary column GLC (2). Today, GC is the
preferred method of analysis of fire debris (1, 4-6, 8-10,
12-14, 16, 17, 20, 21). GC analysis is sometimes
supplemented by energy-dispersive X-ray (EDX) analysis
(12, 18, 19), flashpoint determination (5), and IR
analysis (5, 6, 14, 17, 19-21), although the additional
3
information gained from the latter technique is still
debatable (7).
From the exhaustive, computer-aided literature search
conducted by the author, only two articles mentioned the
possible application of nuclear magnetic resonance (NMR)
spectroscopy analysis of fire debris (12, 18). Although
the work detailed in the two articles was preliminary in
nature, it was thought that NMR could provide the fire
debris analyst with another powerful analytical technique,
complementing the GC methods currently in use.
Scope of the Research
The purpose of the research was to investigate the
possibility of utilizing NMR spectroscopy as an analytical
tool in the analysis of fire debris, to develop a simple
technique that could be utilized in a forensic laboratory,
and to introduce this technique into a scheme of analysis
that would insure a consistent treatment of the fire
debris submitted to a laboratory from receipt of the
debris to the completion of the analysis.
CHAPTER BIBLIOGRAPHY
1. Baldwin, Ronald E., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I(October, 1976T, 5-6.
2. Cain, P. M., "Comparison of Kerosine Using CapillaryColumn Gas Liquid Chromatography," Journal ofthe Forensic Science Society, XV (October,1975), 301-308.
3. Carter, Robert E., "Arson and Arson Investigation inthe United States," Fire Journal, I (July,1980)., 40-46.
4. Criminalistic Methods of Analysis Feasibility Study,The -Forensic Science Foundation, Inc., Colorado,1980.
5. Dean, Bill, "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I(September, 1976) , 2-3.
6. DeHaan, John D., "Laboratory Aspects of Arson:Accelerants, Devices, and Targets," ArsonAnalysis Newsletter, II (August,, 1978TT1-9.
7. DeHaan, John D., "Report on Congress of Criminalists:Arson," Arson Analysis Newsletter, III(February, 1979), 1-8.
8. Edgley, R., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I(October, 197T, 7-8.
9. Graves, Robert L., Hunter, David, and Stewart, LeRoyE., "Accelerant Analysis: Gasoline," ArsonAnalysis Newsletter, I (January, 1977), 5-12.
10. Graves, Robert L. "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I(September, 1976) , 7-8.
11. Incendiarism: An Overview and an Appraisal, a Reporton a Conference on Arson and Incendiarism,Washington D.C., 1975.
4
5
12. Lowry, William Thomas, Stone, Irving C., and Lomonte,John N., "Scientific Assistance in ArsonInvestigation," A report prepared for theCommittee on New Research and Development of theAmerican Society of Crime Laboratory Directors,Southwestern Institute of Forensic Sciences,Texas, 1977.
13. Mach, Martin H., Gas Chromatography - MassSpectrometry of Simulated Gasoline Residues FromSuspected Arson Cases, The AerospaceCorporation, California, 1976.
14. McAtee, William R., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I(October, 197TT, 1.
15. Midkiff, C. R. and Washington, W. D., "GasChromatographic Determination of Traces ofAccelerants in Physical Evidence," Journal ofthe Association of Official Analytical Chemists,VV (July, 1971), 840-845.
16. Midkiff, Charles R., "Separation and Concentration ofFlammable Liquids in Arson Evidence," ArsonAnalysis Newsletter, II (October, 1978), 8-20.
17. Robertson, John A., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter,(October, 1976), 2-3.
18. Stone, I. C., Lomonte, J. N., Fletcher, L. A., andLowry, W. T., "Accelerant Detection in FireResidues," Journal of Forensic Sciences, XXIII(1978) 78-83.
19. Stone, I. C., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I(September, 1976), 5.
20. Thaman, Ronald N., "Chemical Analysis of FireDebris," Arson Analysis Newsletter, I(September, 1976), 9.
21. Thaman, Ronald N., "The Use of DifferentialSpectroscopy in the Analysis of Fire Debris,"Arson Analysis Newsletter, I (September, 1976),11-19.
CHAPTER II
MATERIALS AND METHODS
Choice of Accelerants to be Studied
The accelerants for this study were chosen on the
basis of their frequency of use by arsonists. Table II
lists the results of a study conducted by De Haan (2) and
an unpublished study conducted by the author (1) to
determine the frequency of recovery of different petroleum
distillates from fire debris.
TABLE II
FREQUENCY OF PETROLEUM DISTILLATES RECOVEREDFROM FIRE DEBRIS
Petroleum Percent of Accelerants RecoveredDistillate De Haan (%) Bryce (%)Gasoline 69 77Medium Range petroleum
distillates 15 9Charcoal lighter fluid 6 6Diesel fuel 4 4Kerosine 3 4Cigarette lighter fluid 3 0
The data from this table were considered, so that the
accelerants studied would represent a typical sampling of
accelerants recovered and identified from fire debris
analyzed in a forensic laboratory. Table III lists the
accelerants used in this study.
6
1
'TABLE III
ACCELERANTS STUDIED
Gasolines . . . . . . . . . Texaco unleadedTexaco regularExxon unleadedExxon regularShell unleadedShell regular
Medium range petroleumdistillates. . . . . . . Varsol
Tru-test paint thinnerPainter's naphtha
Others. . . . . . . . . . . Gulf charcoal lighterfluid
Sunnyside KerosineConoco diesel
The brand names were chosen because of their availa-
bility, and they were documented to see whether brands
could be distinguished by this method (3, 4). After
the accelerants were obtained, they were stored in one-
quart metal paint cans in a refrigerator at 2*C to reduce
their volatility and to preserve their original
composition (4).
Preparation of Weathered Accelerants
Samples were taken from the stock accelerants and
placed in 2-mL sample vials. In addition, 40 mL of each
accelerant were evaporated to 10 mL on a hotplate at 90*C,
and were stored in this "weathered" condition (25% Vo)
in 2-mL sample vials.
8
Preparation of Burned and Steam-Distilled
Accelerants
Yellow pine two-by-fours were cut into 6-inch blocks,
and each block was split into 2 pieces and identified by a
scribed tack. One piece of the wood was used as a control
and the other for the sample. Both sample and control
pieces of wood were placed in a 1-quart pyrex dish. 100
mL of an accel erant was poured over the wood and the dish
was then covered. The wood was allowed to soak in the
accelerant for 3 minutes. Both pieces of wood were then
removed and placed on a 9" x 9" pane of glass and allowed
to dry for 1 minute. Next, the control was immersed in a
new gallon paint can filled with 1/2 gallon of water and
sealed with a lid. The sample piece of wood was then
ignited with a match on the glass pane under a fume hood
and allowed to burn for 1 minute. The flame was then
extinguished with an air jet and the sample was immersed
in a similar paint can as the control and sealed. Both
pieces of wood were then steam distilled for one hour
following the procedure described by Stone (3). Fi gure 1
illustrates the steam distillation apparatus used. The
distillate was then collected, dried with sodium chloride,
and placed in 2-mL sample vials.
9
debris container
electric hot plate
FIG. -- Steam distillation apparatus
cold water,'condenser
accelerant trap
around glass adapter
10
Analysis
The four samples of each accelerant--virgin,
weathered, steam distilled, and burned-steam distilled,--
were analyzed by gas chromatography and with a Hitachi
Perkin-Elmer R124A Nuclear Magnetic Resonance Spectro-
meter. The gas chromatograph's six-foot column was packed
with 3% SP2100. The gas chromatograph was equipped with a
flame ionization detector. Deuterated chloroform was used
as a solvent and tetramethylsilane was used as an internal
standard for the NMR analysis.
Solvent Study
A study was also conducted using several NMR solvents
to see whether there was any effect on the resulting
spectra. The solvents used were deuterated chloroform,
carbon tetrachloride, deuterated acetone, carbon
disulfide, and no solvent (neat sample). A 10% gasoline--
90% solvent mixture was analyzed using nuclear magnetic
resonance spectroscopy.
Detectibility Limit Study
An analysis of 5%, 3%, and 2% gasoline-carbon
tetrachloride samples was performed using nuclear magnetic
resonance spectroscopy to determine the detectibility
limits and effects of concentration on the analysis.
CHAPTER BIBLIOGRAPHY
1. Bryce, Kenneth L., "Frequency of AccelerantsRecovered and Identified by the SouthwesternInstitute of Forensic Sciences for the YearEnding July 31, 1980," unpublished technicalreport, Southwestern Institute of ForensicSciences, Dallas, Texas, 1980.
2. De Haan, John D., "Laboratory Aspects of Arson:Accelerants, Devices, and Targets," ArsonAnalysis Newsletter, II (August 1978T, 1-9.
3. Mach, Martin H., Gas Chromatography--MassSpectrometry of Simulated Gasoline Residues FromSuspected Arson Cases, The AerospaceCorporation, California, 1976.
4. Stone, I. C., J. N. Lomonte, L. A. Fletcher, andW. T. Lowry, "Accelerant Detection in FireResidues," Journal of Forensic Science, XXIII(1978) 78-83.
5. Willson, David, "A Unified Scheme for the Analysis ofLight Petroleum Products Used as Fire Accel-erants," Forensic Science, X (1977) 243-252.
11
CHAPTER III
RESULTS AND DISCUSSION
Steam Distillation of Accelerants
Table IV lists the amounts of accelerants recovered
from the burning-steam distillation procedure.
TABLE IV
DISTILLATE COLLECTED BY STEAM DISTILLATION
Petroleum Distillate Control Burned(mL) (mL)
Texaco Unleaded Gasoline 0.6 0.2Shell Unleaded Gasoline 0.5 0.2Varsol 0.6 0.1Tru-Test Paint Thinner 0.5 0.2Gulf Charcoal Lighter Fluid 0.5 0.2Sunnyside Kerosine 0.4 0.2Conoco Diesel 0.4 0.1
Separation of the accelerant from the substrate via steam
distillation yielded enough distillate to analyze by GC
and NMR spectroscopy analysis.
Interpretation of Spectra
Figure 2 shows two NMR spectra whose chemical shifts
are expressed in viunits, relative to tetramethylsilane.
For accelerants, a spectrum can be divided into four major
regions: aliphatic portion (A) (0-2 ppm), aliphatic
moieties of aromatic components (B) (2-3 ppm), a dead
12
D
7.5 6.5
a
b
C
3.0 2.0
FIG. 2 -- NMR spectra of (a) benzene, toluene, and xylenemixture, and (b) Texaco unleaded gasoline.
13
y4~JA
0 ppm
I B
14
space where no large peaks are observed (C) (3-6.5 ppm),
and an aromatic region (D) (6.5-7.5 ppm). No peaks were
observed farther downfield than about 7.5 ppm. Notice in
the gasoline spectrum that the peaks contained in the B
and D regions are due, at least in part, to the benzene;
toulene, and xylene components. These components are
easily identified and are present to some extent in many
accelerants, especially gasoline (2). From inspection of
the spectra obtained, it can be seen that the relative
size and shape of the peaks in region A are strongly
indicative of any particular accelerant. Therefore, by
noting the relative sizes of the peaks, the accelerant can
be identified. Figure 3 shows that, regardless of the
condition of the accelerant, the general relative
abundance of the B and D peaks remains fairly constant.
It was found that an accelerant could be identified by NMR
regardless of the condition of the accelerant. This
identification is not always possible by GC analysis, as
burning or separating the accelerant can cause a loss of
components, which can complicate identification (8).
Figures 4-14 show NMR spectra of the accelerants studied.
Note that each accelerant has its own unique pattern and
relative B and D peak shapes and abundances. This unique
pattern for each accelerant varies only slightly due to
l
15
a
b
c
d,
7.5 6.5 3.0 2.0 0 ppm
FIG. 3 -- NMR spectra of Texaco unleaded gasoline:(a) virgin; (b) weathered; (c) steam distilled; (d) burned-steam distilled.
16
a
b
1']
C
~ /qr~
d
'MI.
6.5 3 0 2.0 0 ppm
FIG. 4 -- NMR spectra of Shell unleaded gasoline:(a) virgin; (b) weathered; (c) steam distilled; (d) burned-steam distilled.
7.5
oll
IA
a
b
........
17
C
SAA%
d---
6.5 3.0 2.0 0 ppm
FIG. 5 -- NMR spectra of Varsol: (a) virgin; (b) weathered;
(c) burned-steam distilled; (d) steam distilled.
7.5
- - . -- W^
18
a
b
C
a
7.5 6.5 3.0 2.0 0 ppm
FIG. 6 -- NMR spectra of Tru-Test paint thinner:
(a) virgin; (b) weathered; (c) steam distilled; (d) burned-
steam distilled.
------------ I-
a
b
C
~-~,--
19
a
6.5 3.0 2.0 ppm
P IG. 7 -- NMR spectra of Sunnyside kerosine: (a) virgin;
(b) weathered; (c) steam distilled; (d) burned-steam distilled.
-. t 1
7.5
,-4---
20
,1~
a
b
'If
/1'
.
I II 1
7.5 6.5 3.0 2.0
C
FIG. 8 -- NMR spectra of Gulf charcoal lighter fluid:
(a) virgin; (b) weathered; (c) steam distilled; (d) burned-
steam distilled.
I - - -
0 ppm
.. P.-v -4 WA -a kll
I
I
21
aA
b
C
d
7.5 6.5 3.0 2.0 0 ppm
FIG. 9 -- NMR spectra of Conoco diesel: (a) virgin;
(b) weathered; (c) steam distilled; (d) burned-steam distilled.
22
a
b
g Wwt
~
I1ii
6.5 3.0 2.0 0 ppm
FIG. 10 -- NMR spectra of Texaco regular gasoline:
(a) virgin; (b) weathered.
7.5
I
23
a
b
1 1 1
7.5 6.5 3.0 2.0
FIG. 11 -- NMR spectra of Shell regular gasoline:
(a) virgin; (b) weathered.
frI\~I I
-40 ppm.
II i I
24
a
.44
I I I
3.0 2.0 0 ppm
FIG 12 -- NMR spectra of Exxonr'unleaded gasoline:
(a) virgin; (b) weathered.
I b
7.5 6.5
I'I
6.5
a
b
7.5 3.0 2.0
FIG. 13 -- NMR spectra of Exxon regular gasoline:
(a) virgin; (b) weathered.
25
0 ppm
II I
26
a
1~
b
.4
3.0 2.0 0 ppm
FIG. 14 -- NMR spectra of painter's naphtha: (a) virgin;
(b) weathered.
7.5 6.5
i
-v
-A- .-- A-
27
sample condition and brand of products, so that one is
unable to distinguish between brands of a product. This
conclusion is supported in the literature (4, 5).
Using the NMR technique, it is easy to distinguish
among gasoline, medium range petroleum distillates
(Varsol, paint thinner, naphtha, charcoal lighter fluid),
and heavy petroleum distillates (kerosine, diesel), while
distinction within a class can be accomplished with a
well-tuned instrument.
Figures 15-24 are gas chromatograms of the
accelerants studied. They have been included for
documentation and for experimental control. It can be
seen that evaporation of the accelerant can greatly alter
its gas chromotograph.
Solvent Study
The solvent study revealed that the solvent used has
no appreciable effect on the spectrum obtained. Carbon
tetrachloride can be used to obtain the same quality
spectrum as the noxious-smelling carbon disulfide and the
more expensive deuterated chloroform. The sample can even
be analyzed without the use of a solvent (neat) in those
situations where very little distillate is obtained and
further analysis is desired.
28
a
FIG. 15 -- Gas chromatograms of Texaco unleaded gasoline:
(a) virgin; (b) weathered.
b I
29
a
b
FIG. 16 -- Gas chromatograms of Texaco regular gasoline:
(a) virgin; (b) weathere:.
30
a
2
FIG. 17 -- Gas chromatograms of Exxon unleaded gasoline:
(a) virgin; (b) weathered.
b
31
b
K\ ~Y\Af\ \~WA~J
N
FIG. 18 -- Gas chromatograms of Exxon regular gasoline:
(a) virgin; (b) weathered.
L
a
32
'4 - \~x fVF\j Krk~,
bj
FIG. 19 -- Gas chromatograms of Shell unleaded gasoline:
(a) virgin; (b) weathered.
a
33
Ia
b.
FIG. 20 -- Gas chromatograms of Shell regular gasoline.
(a) virgin; (b) weathered.
a
I
b
K 1 ~ l
KNiJ
FIG. 21 -- Gas chromatograms of Varsol: (a) virgin;
(b) weathered.
34
i Y
35
a
______g\j\
b
FIG. 22 -- Gas chromatograms of Tru-Test paint thinner:
(a) virgin; (b) weathered.
a'I
b
FIG. 23 -- Gas chromatograms of Gulf charcoal lighterfluid: (a) virgin; (b) weathered.
36
a
FIG. 24 -- Gas chromatograms of Sunnyside kerosine:(a) virgin; (b) weathered.
37
K
b
HI
38
Detectibility Limit Study
The detectibility limit study was encouraging,
showing that, in the case of gasoline, identification can
be made at a 2% level of concentration (Figure 25).
Case Studies
After the NMR method was researched, it was applied
to actual cases submitted to the Southwestern Institute of
Forensic Sciences in Dallas, Texas. Figure 26 shows
spectra of gasoline from two cases submitted to the
laboratory. Note that (b) matches the standard gasoline
spectrum nicely. The (c) spectrum sample was distilled
from severely burned and dehydrated debris. Upon GC
analysis, it was concluded that gasoline could be present,
but there were too many interfering peaks to make a
positive identification. The NMR spectrum, however,
reveals the presence of gasoline in the sample. Because
the NMR is not as sensitive to minute quantities of a
compound as GC, interfering substrate does not offer the
problems with the NMR technique as it does with GC.
In Figure 27, the charcoal lighter fluid and kerosine
spectra are from cases submitted to the laboratory.
Similarities to the standards already presented are
readily apparent. Spectrum (c) is an example of a typical
non-accelerant type distillate obtained from a case
sample. An interesting aspect of the NMR method is seen
S
ICdl
I
E4
04
o\OCN
0\0
0
4
39
C) 00 U)
rdca
r-
0
Cd
04
Z'LO
Ln
CN
Ha
40
b
C
7.5 6.5 3.0 2.0 0 ppm
FIG. 26 -- NMR spectra of gasolines: (a) gasoline;
(b) case spectrum; (c) case spectrum.
41
a
b
C
_I - - I
7.5 6.5 3.0 2.0 0 ppm
FIG. 27 -- NMR spectra of case studies: (a) charcoal
lighter fluid; (b) kerosine; (c) negative accelerant spectrum.
I I I I
42
here, in that the peaks between 5.0 and 7.1 can be
attributed to styrene, a common interfering species.
Merits and Limitations
The merits of the NMR technique are significant
enough to be considered by the analyst for use in cases of
suspected arson. It has purposely been kept simple so
that it can be easily adapted to the specific needs of the
analyst. The procedure has been used by the Dallas County
Forensic Laboratory in cases involving fuel contamination
and gasoline seepage, as well as arson. As already seen,
it aids in the identification of interfering species and
is not sensitive to small amounts of interfering species,
which is a major problem with present methods of analysis
(2, 7, 8). Another advantage of the NMR method is that
spectra of standards and samples from different
laboratories are easily compared, which is not necessarily
true for GC, due to the diversity of columns and
instrumental parameters in use today (6).
The method suggested in this paper represents an
unconventional use of NMR spectroscopy. This can be
partially attributed to the composition of accelerants,
which are sometimes mixtures of hundreds of components (3).
This makes peak splitting studies ineffective.
Integration is also ineffective due to the change of peaks
which occurs because of evaporation, weathering, and
43
distillation. More elaborate NMR techniques could have
been studied, but looking for peaks in specific regions of
the spectrum and comparing their relative intensities to
other peaks should yield an easy, quick, and specific
analysis with the advantage of simplicity.
Two drawbacks were discovered with the procedure. As
previously reported, NMR is less sensitive than GC, which
could present a problem if only a minute concentration of
accelerant is present in the sample. Also, separation of
the accelerant from the burned debris is a necessary
prerequisite to analysis.
Scheme of Analysis
As stated earlier, the scope of the research included
the introduction of the NMR method of analysis into to a
scheme of analysis that would insure a consistent
treatment of the fire debris submitted to a laboratory
from receipt of the debris to the completion of the
analysis. This was best accomplished by developing a flow
chart similar to that illustrated in Figure 28 (1). The
scheme of analysis which was developed appears as Figure
29.
H H
* 0
U* 0
0 H
H
H
0
P I-
ro zHE-1
E-O
44
U)
F: -1
uJ)zXrd
4
U)
Ul0
(1)
>1
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CHAPTER BIBLIOGRAPHY
1. Criminalistic Methods of Analysis Feasibility Study,Colorado, The Forensic Science Foundaiton, Inc.,1980.
2. Graves, Robert L., Daniel Hunter and LeRoy E.Stewart, "Accelerant Analysis: Gasoline," ArsonAnalysis Newsletter, I (January, 1977), 5-12.
3. Hrynchuk, R., R. Cameron and P. G. Rogers, "VacuumDistillation for the Recovery of FireAccelerants From Charred Debris," CanadianSociety Forensic Science Journal, X (1977),41-50.
4. Mach, Martin H., Gas Chromatography-Mass Sepctrometryof Simulated Gasoline Residues From SuspectedArson Cases, The Aerospace Corporation,California, 1976.
5. Midkiff, Charles R., "Brand Identification andComparison of Petroleum Products - A ComplexProblem," The Fire and Arson Investigator, XXVI(1975), 18-21.
6. Saferstein, R., "Letter to Arson AnalysisNewsletter," Arson Analysis Newsletter, I(1977), 1-12.
7. Thaman, Ronald N., "Chemical Analysis of FireDebris," Arson Analysis Newsletter, I(September, 1976) , 9.
8. Willson, David, "A Unified Scheme for the Analysis ofLight Petroleum Products Used as FireAccelerants," Forensic Science, X (1977),243-252.
46
BIBLIOGRAPHY
Articles
Baldwin, Ronald E.., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I (October,1976), 5-6.
Cain, P. M., "Comparison of Kerosine Using CapillaryColumn Gas Liquid Chromatography," Journal of theForensic Science Society, XV (October, 1975~)301-308.
Carter, Robert E., "Arson and Arson Investigation in theUnited States," Fire Journal, I (July, 1980), 40-46.
Dean, Bill, "Letter to the Arson Analysis Newsletter,"Arson Analysis Newsletter, I (September, 1976), 2-3.
DeHaan, John D., "Laboratory Aspects of Arson:Accelerants, Devices, and Targets," Arson AnalysisNewsletter, II (August, 1978), 1-9.
DeHaan, John D., "Report on Congress of Criminalists:Arson," Arson Analysis Newsletter, III (February,1979)3, 1-8.
Edgley, R., "Letter to the Arson Analysis Newsletter,"Arson Analysis Newsletter, I (October, 1976), 7-8.
Graves, Robert L., Hunter, Daniel, and Stewart, LeRoy E.,"Accelerant Analysis: Gasoline," Arson AnalysisNewsletter, I (January, 1977), 5-12.
Graves, Robert L., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I (September,1976), 7-8.
Hrynchuk, R., Cameron, R., and Rogers, P. G., "VacuumDistillation for the Recovery of Fire AccelerantsFrom Charred Debris," Canadian Society ForensicScience Journal, X (1977), 41-50.
McAtee, William R., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, I (October ,1976), 1.
47
48
Midkiff, Charles R., "Brand Identification and Comparisonof Petroleum Products--A Complex Problem," The Fireand Arson Investigator, XXVI (1975), 18-21.
Midkiff, Charles R., Separation and Concentration ofFlammable Liquids in Arson Evidence," Arson AnalysisNewsletter, II (October, 1978), 8-20.
Midkiff, C. R. and Washington, W. D., "Gas ChromatographicDetermination of Traces of Accelerants in PhysicalEvidence," Journal of the Association of OfficialAnalytical Chemists, VV (July, 1971) , 840-845.
Robertson, John A., "Letter to the Arson AnalysisNewsletter," Arson Analysis Newsletter, (October,1976), 2-3.
Saferstein, R., "Letter to the Arson Analysis Newsletter,"Arson Analysis Newsletter,I(1977) , 1-12.
Stone, I. C., Lomonte, J. N., Fletcher, L. A., and Lowry,W. T., "Accelerant Detection in Fire Residues,"Journal ,of Forensic Sciences, XXIII (1978), 78-83.
Stone, I. C., "Letter to the Arson Analysis Newsletter,"Arson Analysis Newsletter, I (September, 1976), 5.
Thaman, Ronald N., "Chemical Analysis of Fire Debris,"Arson Analysis Newsletter, I (September, 1976), 9.
Thaman, Ronald N., "The Use of Differential Spectroscopyin the Analysis of Fire Debris," Arson AnalysisNewsletter, I (September, 1976), 11-19.
Willson, David, "A Unified Scheme for the Analysis ofLight Petroleum Products Used as Fire Accelerants,"Forensic Science, X (1977), 243-252.
Reports
Bryce, Kenneth L., "Frequency of Accelerants Recovered andIdentified by the Southwestern Institute of ForensicSciences for the Year Endinsg July 31, 1980,"unpublished technical report, Southwestern Instituteof Forensic Sciences, Dallas, Texas, 1980, p. 2.
Criminalistic Methods of Analysis Feasibility Study, TheForensic Foundation, Inc., Colorado, 1980.
49
Incendiarism: An Overview and an Appraisal, a Report on aConference on Arson and Incendiarism, Washington,D.C., 1975.
Lowry, William Thomas, Stone, Irving C., and Lomonte, JohnN., "Scientific Assistance in Arson Investigation," Areport prepared for The Committee on New Research andDevelopment of The American Society of CrimeLaboratory Directors, Southwestern Institute ofForensic Sciences, Dallas, Texas, 1977.
Mach, Martin H., Gas Chromatography - Mass Spectrometry ofSimulated Gasoline Residues From Suspected ArsonCases, The Aerospace Corporation, California, 1976.
