Capillary electrophoresis of methylmercury with injection by sample stacking

A procedure for separation and quantitation of methylmercury by capillary electrophoresis using sample stacking as the injection technique is presented. The CE conditions have been optimized in order to separate the methylmercury from the excess cysteine peak and to concentrate large volumes of sample obtaining a low detection limit. Under the proposed operational conditions, the detection limit (S/N=3) was 12 ng g(-1) and the limit of quantitation (S/N=10) was 20 ng g(-1) with a linear range of 20-100 ng g(-1) (as methylmercury in samples). The method was tested using different reference materials with a certified methylmercury content.