8.1
8.1
© Springer-Verlag Berlin Heidelberg 2005
II.8.1 Sarin and its
decomposition products
by Hiroaki Ando and Yoshihiko Miyata
Introduction
Chemical weapons ( chemical warfare agents), such as sarin and soman, were developed to kill
or injure humans by their toxic actions.  ey are called “ nuclear weapon of the poor”, because
the weapons are relatively stable during storage, cheap for production and relatively easily
synthesized with basic knowledge on organic chemistry. Main advanced countries are making
e orts to reduce chemical weapons existing in the world on the basis of the Chemical Weapons
Convention ( CWC), a er the Iran-Iraq War and the Gulf War. In 1990, an incident of human
injury using mustard (yperite) took place at a usual residence at Komagome, Tokyo. In 1994
and 1995, unprecedented sarin poisoning terrorism took place in Matsumoto and Tokyo, Japan
and surprised the whole world in the fear that similar chemical terrorism would be reproduced
in other countries. Also in 1994, an attorney-at-low and his family were killed using VX in
Osaka, Japan.  e above sarin and VX incidents were found committed by the same cult group.
 ese incidents show that chemical weapons can be used not only for wars, but also can be
convenient means of crimes.
To cope with such crimes using chemical weapons, such as yperite and sarin, various pre-
ventive measures should be taken on the basis of the Revised Poisonous and Deleterious Sub-
stances Control Law and the Chemical Weapons Banning Law of Japan; when such an incident
happens, proper and rapid actions should be taken to minimize the damages.
In the list of scheduled chemicals being de ned by CWC, there are toxic chemicals and
precursors for each of Schedules 1–3. In this chapter the word “chemicals” is used for such
scheduled chemicals for simplicity. Before analysis of the chemicals, it is essential to get to
know their histories, methods of synthesis, properties, directions for use, toxicities, therapeutic
methods, stabilities and analytical methods.
 e chemicals directly act on organisms (animals and plants) and exert their toxicities;
they are classi ed into the following 3 groups [1, 2]:

), diisopropyl phosphoro uoridate ( DFP) and N-methyl-N-(tert-butyl-dimeth-
ylsilyl)tri uoroacetamide (MTBSTFA) can be all purchased from Aldrich (Milwaukee, WI,
USA); triisopropyl phosphate, isopropyl hydrogenmethylphosphonate and diisopropyl methyl-
phosphonate were synthesized in our laboratories according to the literature [7].
GC/MS analysis
GC/MS conditions
GC column: an HP-5MS fused silica capillary column (30 m × 0.25 mm i.d.,  lm thickness
0.25 µm, Agilent Technologies, Palo Alto, CA, USA).
GC/MS conditions; injection temperature: 250 °C; injection pressure: 1.05 kg/cm
2
; column
(oven) temperature: 50 °C (2 min) → 20 °C/min → 250 °C (10 min); carrier gas: He (13 psi);
split ratio, 50; ion source temperature: 250 °C; EI electron energy: 70 eV; CI mode reagent gas:
isobutane
c
; CI electron energy: 230 eV; ionization current: 300 µA.
Procedure
i. Direct analysis
A part of the original sarin specimen solution is diluted 10–50 fold with hexane (or acetone)
and injected into GC/MS.
ii. Analysis of decomposition products
i. About 1 g of the above original sarin specimen solution is mixed with 12 mL of 5 % KOH
solution, and le for about 24 h at room temperature. Using the headspace vapor of the
mixture, the absence of undecomposed sarin is con rmed by GC/MS.
ii.  e above aqueous solution is extracted with chloroform (30 mL × 3 times).
iii. A er each centrifugation, the chloroform layers are combined, and dehydrated with anhy-
drous Na
2
SO
4

GC/MS analysis
612 Sarin and its decomposition products
EI mass spectrum of sarin.
⊡ Figure 1.2
CI mass spectrum of sarin.
⊡ Figure 1.3
613
TIC and mass spectra for Peaks 1 and 2 obtained by GC/MS for TBDMS derivatives of hydrolyzed
products of sarin.
⊡ Figure 1.4
⊡ Figure 1.5
EI mass spectrum of VX.
GC/MS analysis
614 Sarin and its decomposition products
shows a CI mass spectrum of VX; an intence protonated peak appeared at m/z 268 together
with fragment peaks at m/z 252, 128 and 114.
NMR analysis
NMR conditions
i. NMR instruments
JNM-EX270 and JNM-EX90A (with the tunable module) FT-NMR spectrometers (JEOL,
Tokyo, Japan) were used.
ii. Analytical conditions
A sample tube with 5 mm i. d. was used. For
13
C, the
1
H decoupling mode was employed;
for
19
F, t he

Assessment of the method
> Figure 1.7 shows a
31
P-NMR spectrum obtained from the original sarin specimen.  e
main doublet signals were judged due to sarin, because they (δ:29.62 ppm, J
PF
= 1037 Hz)
were
almost identical with those of sarin (δ: 28.44 ppm, J
PF
= 1046.3 Hz) reported in literature.
DFP and diisopropyl methylphosphonate could be detected together with sarin by GC/MS
(
> Figure 1.1); in this NMR spectrum, hydrogen methylphosphono uoridate appears in ad-
dition (
> Figure 1.7).
 e
1
H-,
13
C-,
31
P- and
19
F-NMR data for the puri ed sample a er distillation are shown
in
> Table 1.2; the
31
P-NMR data for decomposition products and by-products of sarin shown
in

TMS
trifluoroacetic acid
(δ
F
= –76.5 ppm)
85 % phos-
phoric acid
measurement temperature 26 °C
data point 16 K 16 K 32 K 32 K
NMR lock deuterated chloroform (CDCl
3
)
spectral width (Hz) 1,800.5 7,507.5 26,041.7 8,000.0
pulse width 6.5 µs
(45° pulse)
3.5 µs
(45° pulse)
14.5 µs
(90° pulse)
12.6 µs
(90° pulse)
integration time
(repetition time)
32
(7 µs)
2,400
(3 µs)
64
(3 µs)
256

• Very high toxicity: it should have toxicity, which can kill a number of humans or ani-
mals with a small amount of a poison.
• Stability under certain conditions: upon the use of a poison, the poisonous e ect should
last for a required period; upon its storage, it should be highly stable.
• Low perceptibility of a poison by humans: a compound, which gives a characteristic
smell, a color or a taste, is easily detected by one or more of the  ve senses of humans
⊡ Table 1.2
1
H-,
13
C-,
31
P- and
19
F-NMR data obtained from sarin [5]
Nucleus Chemical shift (ppm) Coupling constants (Hz)
1
H
1-H 1.62 (dd, 3H)
2
J
HP
= 18.5
3
J
HF
= 5.7
2-H 4.90 (m, 1H)
3
J

= 151.2
2
J
CP
= 6.4
3-C 23.74 23.90
1
J
CH
= 126.4
31
P 29.62
2
J
HP
= 18.5
3
J
HP
= 7.3
1
J
PF
= 1045.4
19
F –58.07
3
J
HF
= 5.7

•  ere are types of poisons with early (within several hours) and delayed onset of poi-
soning symptoms.
•  ere are short (within 10 min) and long-acting poisons.
• Because of the low perceptibility of a poison, people are easily exposed and injured by
the poison without any consciousness.
b) sarin/isopropyl hydrogenmethylphosphonate/methyl phosphonic acid
c) As reagent gas, ammonia or methane can be also used.
d)  is compound is an impurity produced by decomposition of methylphosphonic di uo-
ride, the precursor of sarin, or of methylphosphonic chloro uoride, the disproportionation
reaction product.
e) Methylphosphonic dichloride side-reacts with isopropyl alcohol to produce diisopropyl
methylphosphonic acid.
f) DEA is considered to be added to enhance the reaction of the sarin synthesis.
References
1) Wakai H (2000) Defense against chemical weapon attack. Japanese Bureau of the Organization for the Prohibi-
tion of Chemical Weapons (OPCW), Tokyo, pp 142–155 (in Japanese)
2) Komoto T (1995) Basic knowledge on chemical weapons. Criminal Data File of the Metropolitan Police Depart-
ment (Tokyo) 46:17–36 (in Japanese)
3) Ando H (1995) Practical study on sarin analysis at the Tokyo Subway Sarin Incident. In: Abstracts of the 1995
Annual Meeting of Kanto District Society of Forensic Technology. Tokyo, pp 49–56 (in Japanese)
4) Miyata Y, Nonaka H, Yoshida T et al. (2000) Analyses of sarin and related compounds used in the Tokyo Subway
Sarin Incident. Jpn J Forensic Toxicol 18:39–48
5) Miyata Y, Nonaka H, Ando H (2000) Nuclear magnetic resonance data of sarin obtained at the Tokyo Subway
Sarin Incident. Jpn J Forensic Toxicol 18:261–267
6) Miyata Y, Ando H (2001) Examination of an internal standard substance for the quantitative analysis of sarin
using
31
P-NMR. J. Health Sci 47:75–77
7) Japanese Association of Organic Synthetic Chemistry (ed) (1971) Organophosphorus compounds. In: Modern
Organic Synthesis Series (5). Gihodo, Tokyo, pp 329–330 (in Japanese)