Determination of selenomethionine in selenium-enriched yeast using capillary electrophoresis on-line coupled with electrochemiluminescence detection

A new method for the determination of selenomethionine (SeMet) was developed using capillary electrophoresis on-line coupled with electrochemiluminescence detection. The effects of several factors such as detection potential, concentration and pH of phosphate buffer, separation voltage and injection voltage were investigated. Under optimal conditions, the linear concentration range for SeMet was 0.001 to 0.8 mu g mL(-1) with a correlation coefficient of 0.9996. The limit of detection (S/N = 3) was 0.39 ng mL(-1). The recovery of SeMet in selenium-enriched yeast (SEY) was 98.6% on an average. The method presented is simple, quick, sensitive and can be reliably applied to the determination of SeMet in SEY.