With the Chemical Weapons Convention having gone into effect, laboratories that analyze these agents are increasingly important. Analytical Chemistry profiles two groups that are taking different approaches to chemical warfare agent monitoring.
Analytical compet e n c e and the fight against chemical weapons
These real samples typically came from places of alleged use or production of chemical warfare agents, which have been inspected by United Nations officials. Correctly analyzing real samples is critical because a false-positive result would erroneously accuse a chemical company or even a nation of producing chemical weapons. As a result, numerous round-robin and interlaboratory proficiency tests have been organized for method development purposes and, further, to verify the competence of laboratories seeking designation by die OPCW. To become a designated OPCW facility, a laboratory must score well on proficiency tests, must operate under the guidelines of an adequate quality assurance system, and must be accredited by an internationally recognized accreditation body. To date, there have been about 10 international round robins and proficiency tests. The NC Laboratory passed them all with top rankings and also successfully prepared the samples for the first official OPCW proficiency test. In fact, the Analytical Chemistry and Verification branch fulfilled all the requirements for accreditation in the analysis of samples for the presence of chemical warfare agents and related compounds in 1992 and expects to obtain OPCW designation shortly
By April 29,1997, enough states had ratified the international Chemical Weapons Convention (CWC)—which prohibits the development, production, storage, and deployment of these weapons—that the treaty went into effect. With the convention has come the difficult task of enforcing the previsions—and that is putting significant demands on analytical chemistry. The Organization for the Prohibition o: Chemical Weapons (OPCW), seated in The Hague (The Netherlands), is in charge of the worldwide surveillance of CWC compliance. OPCW, in turn, has been recruiting teams of inspectors and designated laboratories to specialize in the analysis of various samples for the presence of chemical warfare agents and related compounds. One of the leading laboratories in this conplex area is the NC Laboratory in Spiez, The proficiency testing has been a rigSwitzerland (NC stands for Nuclear and orous process. A typical scenario is as folChemical threats and risks). lows: One of the about 25 laboratories participating in the test prepares the samples, The Swiss Federal Military Department such as soil, water, clothing and so on, originally established the NC Laboratory as which are contaminated with an unknown a technical facility for developing ways to number of different chemicals (as well as protect against chemical weapons. As the diesel oil, plasticizers, or other compounds demand for such studies has lessened, part that will confound the of the laboratory has analytical data). The instead become a facility other laboratories must for inspection and verififind and identify all cation. "So far we have relevant chemicals. been busy with the establishment of certified To illustrate how analytical methods for demanding even a the qualitative and quanqualitative analysis titative determination of can be, consider the compounds related to class of nerve agents the CWC with participaencompassing the altion in international kylphosphonofluoriround-robin and profidates (see above). ciency tests and with According to the acthe analysis,of real samtual lists of chemicals ples " says Andreas to be surveyed under Niederhauser head the CWC R can be the six-person Analytical methyl, ethyl, n- or Chemistrv and Verificawo-propyl, and the alFT-IR at work in a chemical weapons tion groun kyl substituent R' can lab.
be anything from C1 to C10, including branched and cyclic isomers. (A well-known compound in this class is Sarin with R = The general structure methyl and R' = of the alkylphosphonoisopropyl.) Befluoridates. cause many other classes of chemical warfare agents, precursors, and degradation products are included in the CWC lists, it is obvious that a huge number of dangerous chemicals could exist that are neither commercially available nor have been synthesized. In the Spiez NC Laboratory the samples are analyzed simultaneously by various approaches because at least two different, preferably spectroscopic, methods will be necessary for positive identification. However, it is not known in advance which are successful. Sample preparation is rather specific and depends on the type of matrix. Various couplings of chromatography with spectroscopy or special detectors are used: GC/MS (different ionization techniques), GC/FT-IR GC/atomic emission detector (which gives a fast identification of heteroatoms present in a certain compound), GC/flame photometric detector, LC/MS (different ionization techniques) or CE/ MS If enough sample is available the structure can be identified by NMR Usually the confirmation is done by compounds synthesized in the organic chemistry branch of the NC Laboratory which maintains a large number of precursors in stock and has developed protocols for the rapid preparation of compounds With CWC just getting started, Niederhauser and his team expect numerous opportunities to continue to refine their analytical competence to a high level. Veronika Meyer
Frequent flyer lab Can a fully equipped lab buckle its seat belt and travel to where it's needed most? This means tackling emergency analyses and getting evidence expediently. Flying laboratories are designed to fight terrorism and chemical weaponry by analyzing air, soil, and water on location. Called "Mod-U-Lab" by some and "FlyAway-Lab" by others, these mobile labora-
Analytical Chemistry News & Features, January 1, 1998 21 A
