Determination of mercury compounds by capillary electrophoresis inductively coupled plasma mass spectrometry with microconcentric nebulization

A preliminary study of a microconcentric nebulizer (MCN) as the sample introduction device for the capillary electrophoresis inductively coupled plasma mass spectrometry (CE-ICP-MS) system for mercury speciation application is described. Samples containing ionic mercury compounds were subjected to electrophoretic separation before injection into the microconcentric nebulizer. The species studied include inorganic mercury (Hg(II)), methyl mercury (CH3-Hg) and ethyl mercury (C2H5-Hg). The sensitivity, detection limit and repeatability of the CE-ICP-MS system with a microconcentric nebulizer were comparable to CE-ICP-MS system with other nebulization techniques of various metal speciation studies. Reproducibility of peak height and migration time was better than 3 and 2%, respectively. The limits of detection for various mercury species were in the range of 0.08-0.17 mu g ml(-1) Hg based on peak height. We determined the concentrations of mercury compound in contact lenses solutions purchased from the local market. The precision between sample replicates was better than 7% with CE-MCN-ICP-MS method. (C) 2000 Elsevier Science B.V. All rights reserved.