3-Mercaptopropyltrimethoxysilane coated capillary micro-extraction coupled to capillary electrophoresis for the determination of methylmercury, phenylmercury and mercury in biological sample

A simple method for the separation of methylmercury, phenylmercury and mercury(II) in biological sample was developed. The novel method was targeted on extraction of mercury species using a 3-mercaptopropyltrimethoxysilane coated capillary, and determined by capillary electrophoresis with ultraviolet absorption detection. The effects of pH, sample volume and flow rate, eluent volume and flow rate on the efficiency of micro-extraction were investigated. Under the optimized conditions, the detection limits (S/N?=?3) of MeHg, PhHg and Hg²⁺ were 0.012, 0.007 and 0.003 µg mL^?1, respectively. The precisions (RSDs) of the peak area and the migration time for five replicate injections of the three species after capillary micro-extraction were 6.4%, 8.3%, 5.3% and 1.2%, 1.3%, 1.8%, respectively. The method was successfully applied to the determination of mercury species in biological sample.