Page 289 - Advances in Forensic Applications of Mass Spectrometry - Jehuda Yinon

1522_book.fm Page 260 Thursday, November 13, 2003 9:58 AM

CH 2 ONO 2 CH 2 ONO 2
CH 2 ONO 2
CHONO 2 O 2 NOCH 2 C CH 2 ONO 2
CH 2 ONO 2
CH 2 ONO 2 CH 2 ONO 2

EGDN NG PETN
Scheme 7

booster charges, and in plastic explosives (such as Semtex and
Detasheet). 1,20,28 The chemical stability of PETN is very high. It is highly
sensitive to impact and to initiation by explosion, but not very sensitive to
friction. Its melting point is 141˚C. It is most soluble in acetone (20 g/100 g
at 20˚C) and in ethyl acetate (6.3 g/100 g at 19˚C), and very slightly soluble
–8
o
in water (0.2 mg/100 g at 20˚C). Its vapor pressure at 25 C is 1.4 ¥ 10 Torr.
NG is a colorless, odorless, and viscous liquid with a burning sweetish
taste. 1,20,28 NG has been the main component in many dynamites and is an
28
ingredient in multibase propellants. It is very sensitive to shock, impact,
and friction, and is used only when desensitized with other liquids or absor-
bent solids, or when mixed with nitrocellulose. NG is also used as a vasodi-
lator in the treatment of angina pectoris. Its melting point is 13.2˚C, and it
is miscible with ether, acetone, chloroform, ethyl acetate, dichloroethylene,
benzene, and nitrobenzene. Solubility in water is 0.15 g/100 g. Its vapor
pressure is 2.5 m Torr at 20˚C.
EGDN (also known as nitroglycol) is a transparent, colorless, liquid
explosive. It is less sensitive to impact than NG and is considered to be more
stable than NG. EGDN is very soluble in acetone, benzene, ethanol, diethyl
ether, chloroform, and toluene. Its solubility in water at 20˚C is 0.5 g/100 g.
Its vapor pressure is 70 m Torr at 25 C. EGDN has been used in mixture
o
with NG for low-temperature dynamites, as its melting point is –22.8 C.
o
Several additives were tested with a series of explosives, including EGDN,
22
NG, and PETN. Mobile phase of methanol–water (50:50) with 1 mM
ammonium nitrate as additive produced best results, forming major [M +
NO ] ions. EGDN formed nitrate adduct ions only for sample sizes of at
–
3
least 500 ng. The base peak in the ESI mass spectrum of NG was at m/z 289,
–
–
[M + NO ] , but it had also an ion at m/z 226, [M – H] , having a 35%
3
abundance.
Electrospray ionization coupled with tandem mass spectrometry was
used for the analysis of a series of explosives, including NG and PETN. 21
Analyses were performed with a Perkin–Elmer Sciex API III-PLUS triple
quadrupole mass spectrometer with electrospray ionization. Standard solu-
tions of NG and PETN were made in acetonitrile–water (50:50), containing

© 2004 by CRC Press LLC