Biolabor Trauen
Working group cwa analysis
Hazard Control GmbH, Versuchsfeld Trauen, D-29328 Faßberg
Dipl. Ing. Alfred Krippendorf, email: Hazard.Control.GmbH@t-online.de
Büro für Altlastenerkundung und Umweltforschung, Stadtwaldstr. 45a,
D-35037 Marburg
Dr. Rainer Haas, email: haasr@gmx.net
Analytical examination of arsenical chemical warfare agents
Arsenic-containing CWA as phenylarsines, alkylarsines and chlorovinylarsines can chemicaly degrade under certain environmental conditions.
The chemical behaviour eg of the phenylarsines and diphenylarsines is influenced by several factors:
1) The phenyl-arsenic bonding is very stable. The phenylarsine and the diphenylarsine sections remain unchanged and only under extreme conditions are these sections destroyed.
2) Phenylarsines and diphenylarsines are oxidized by oxidants to phenylarsons and diphenylarsons respectively. In the presence of water, phenylarsonic acid and diphenylsonic acid arise respectively.
3) Chloride and cyanide are easily disposed of. Substitution reactions can occur under mild conditions, but these reactions are ocassionally incomplete. A pH value dependent equilibrium can arise.
Triphenylarsine is relatively stable under environmental conditions, triphyenylarsine oxide can arise through oxidation.
It is absolutely necessary that through the examination of water and soil samples, that apart from the original substances, the degredation products are also analyzed. Some of these degredation products can be not be detected by HPLC or GC, and so examination after derivatization with mercaptanes and dimercaptanes is necessary.
Furthermore, the recognition and consideration of degredation reactions is necessary during the preparation of the sample and the chemical-analytical examination, eg: the reaction of diphenylarsine chloride and cyanide with methanol (product: diphenylarsine methylether).
Through the kinetic examination of important chemical, biochemical and eco-toxiological model reactions, important information pertaining to the reaction conditions of the phenylarsines and diphenylarsines can be gained. Regarding questions of the stability or reactivity of phenylarsines and diphenylarsines in various organic solutions, we have undertaken long-term studies.
The following methods for the quantitative examination of phenylarsines, alkylarsines and chlorovinylarsines (LEWISITE) were developed and can be utilized with the consideration of their reactivity.
* quantitative examination of phenylarsine dichloride (PFIFFIKUS), diphenylarsine chloride (CLARK I), diphenylarsine cyanide (CLARK II), ethylarsine dichloride, bis(2-chlorovinyl)chloroarsine (LEWISITE II) and tris(2-chlorovinyl)arsine (LEWISITE III);
method: GC/ECD (electron capture detector) and/or GC/FID (flame ionisation detector)
* quantitative examination of phenylarsines (sum after hydrolysis), diphenylarsines (sum after hydrolysis), phenarsazine chloride (ADAMSIT, after Hydrolysis), triphenylarsine, triphenylarsine oxide, phenyl arsonic acid, diphenyl arsonic acid, ethylarsines (sum after hydrolysis), LEWISITE I, LEWISITE II and LEWISTTE III;
method: HPLC/DAD (diode array detector)
* quantitative examination of phenylarsines, diphenylarsines, ethylarsines, LEWISITE I and LEWISITE III and their oxidation and hydrolysis products after derivatization with mercaptanes and dimercaptanes;
method: GC/ECD
* quantitative examination of sulfur mustard, oxygen mustard, sesquimustard and their degradation products;
method: GC/MS
* identification with GC/MS or HPLC/MS (mass spectrometry).
Various substances for the
derivatization of the phenylarsenic compounds are avilable, and so
disturbances arising from the matrix can be eliminated.
Dr. Rainer Haas, Dipl. Ing. Alfred Krippendorf
Get more informations via email (haasr@gmx.net) and (Hazard.Control.GmbH@t-online.de).