Possibilities of determination of mercury compounds using capillary zone electrophoresis

Abstract

Capillary zone electrophoresis (CZE) has been used to separate inorganic (Hg 2+) and organic mercury (methyl-, ethyl- and phenylmercury) compounds. In order to achieve the proper CZE separation and UV detection of mercury compounds, their different complexes had to be formed. The advantages of four different complexing agents having thiol group (cysteine, glutathione, 2-mercaptonicotinic acid and mercaptoacetic acid) were studied. In the case of all four agents the optimized electrophoretic separation was achieved in fused silica capillary at 25 kV using 25 mM sodium borate buffer (pH 9.3). Identification and quantification of the mercury species at mg/l levels was carried out by the use of UV spectrophotometric detection at 200, 260 and 300 nm depending on the used complexing agent.