Capillary Electrophoresis in Detection of Chemicals Related to the Chemical Weapons Convention

Abstract

This article describes the application of capillary electrophoresis (CE) to the analysis of compounds relevant to the Chemical Weapons Convention (CWC). CE is an analytical technique that employs narrow‐bore, fused‐silica capillaries to perform high‐efficiency separations of analytes based on their mobilities in an electric field. In CE, analytes are dissolved in a buffer solution and placed in a capillary to which an electric field is applied. The analytes then migrate at a rate determined by their charge and size and are detected as they migrate past a detector. CE can analyze a broad range of compounds and is particularly applicable to the analysis of water‐soluble degradation products of scheduled compounds under the CWC. Compounds typically analyzed by CE include the hydrolysis products of nerve agents such as the alkylphosphonates and hydrolytic or oxidative products of the sulfur mustards such as thiodiglycol. The alkyphosphonates require the use of indirect ultraviolet (UV) detection or other detection methods as they do not possess a suitable UV chromophore. Degradation products of the sulfur mustards have been analyzed by micellar electrokinetic chromatography (MEKC) and direct UV detection. The ability of CE to analyze anionic, cationic, zwitterionic, and neutral CWC‐related compounds, whether they be chemical warfare (CW) degradation products or scheduled starting materials, without the requirement for elaborate sample processing or labeling procedures, is an important demonstration of the utility of CE for the analysis of CWC‐related compounds. CE can be an important screening method for rapid sample processing and further analysis for unambiguous identification. The relative ease of analysis should also increase its utility in field and on‐site analysis where minimizing the logistic burden is attractive.

Analysis of nerve agent degradation products in high‐conductivity matrices by transient ITP preconcentration and CZE separation coupled to ESI‐MS

“…A variety of electrophoretic preconcentration techniques, however, can be used to enhance sensitivity in CE [2][3][4][5]. Preconcentration principles based on electric field amplification such as field-amplified sample stacking, field-amplified sample injection or large volume sample stacking can be applied to analytes present in matrices of lower conductivity than the BGE, but they are Mé lanie Lagarrigue 1 not relevant when this condition is not fulfilled. The preconcentration of analytes contained in high-conductivity matrices [6] such as seawater [7][8][9], urine [10][11][12][13], serum [10,[14][15][16][17] or plasma [11] prior to CZE separation can be performed using ITP.…”

“…or in the biological fluids of the victims (urine, plasma, blood, etc.). Although less used than GC or LC, CE has been recognized as an interesting technique for the analysis of chemical warfare agents [1], but it generally suffers from a low concentration sensitivity, which is due to the limited injection volume (ca. 1% of the capillary volume under classical conditions).…”