Chemistry Reference
In-Depth Information
No chromogenic method is available to qualitatively distinguish between phos-
gene, diphosgene, and triphosgene in the liquid phase, at the interface between the
liquid and gas phases, or in the gas phase.
The color reaction of triphosgene with Harrison's reagent (a mixture of 4-(N,N-
dimethylamino)benzaldehyde and diphenylamine in a non-aqueous solvent) yields
a yellow to deep-orange hue, according to the concentration [19].
In the laboratory or in other small-scale operations, specific Draeger tubes are
used to detect phosgene. Information on suppliers of such equipment can be
found on the Internet. The Data Sheet for phosgene badges lists the following posi-
tive interferences: dust, chloroformates, cyanuric chloride, carbonyl bromide; some
phosgene derivatives such as carbonates are also detected. On the other hand, ace-
tyl chloride, oxalyl chloride, chlorine, and very high concentrations of hydrogen
chloride will suppress the response to phosgene.
For the use of the React-IR technique to distinguish between chlorinated equiv-
alents and to monitor triphosgene decomposition, see [20].
For the quantitative determination of triphosgene, the recommended methods
are the same as those for phosgene:
.
Colorimetric method: after reaction of 4-(4
0
-nitrobenzyl)pyridine and N-benzyl-
phenylamine in diethyl 1,2-benzenedicarboxylate, exposure to triphosgene pro-
duces a brilliant red color.
.
Titration: phosgene and triphosgene liberate iodine from sodium iodide in ace-
tone.
.
Argentometric titration: titration of the liberated chloride ions after hydrolysis.
For a quantitative determination in large-scale chemical processing, automatic gas
level sensors, such as the OLDHAM-GZ-ARRAS (France) M/42, having a four-
channel programmable alarm system, are used [19]. Electrochemical phosgene
detectors (0.1-3.0 ppm) and handy pumps with phosgene tubes (AUER GAS-
TESTER II) (from 0.1 ppm) are also employed.
8.4
References
1
T. A. Ryan, C. Ryan, E. A. Seddon,
K. R. Seddon, Phosgene and Related
Carbonyl Halides, Elsevier,
Amsterdam, 1996.
2
T. C. Marrs, R. L. Maynard, F. R.
Sidell, Chemical Warfare Agents.
Toxicology and Treatment, J. Wiley &
Sons, Chichester, 1996, p. 185-202.
3
A. M. Mehlman, Def. Sci. J. 1987,
37(2), 269-279.
4
U. P. Kodavanti, D. L. Costa, S. N.
Giri, B. Starcher, G. E. Hatch,
Fundam. Appl. Toxicol. 1997, 37(1),
54-63.
5
B. J. Jugg, P. Rice, D. A. Berg (Eds.),
Proc. ERDEC Sci. Conf. Chem. Biol.
Def. Res. 1996, Meeting Date 1994,
205-210, Publisher: National Techni-
cal Information Service, Springfield,
Va.; Chem. Abstr. 1997, 127, 1763.
6
A. P. Polednak, D. R. Hollis, Toxicol.
Ind. Health 1985, 1(2), 137-147.
J. Santodonato, Cent. Chem.
Harvard Assessment, Syracuse Res.
7
