Determination of 5-hydroxytryptamine in serum by electrochemiluminescence detection with the aid of capillary electrophoresis.

A rapid, sensitive and simple electrochemiluminescence method for the determination of 5-hydroxytryptamine (5-HT) using capillary electrophoresis was proposed. The experimental parameters, including the detection potential, the concentration of Ru(bpy)(3)(2+), the concentration and pH of phosphate buffer for separation and detection, the injection voltage and time and the separation voltage on the determination of 5-HT, were optimized. Under the optimized conditions, the linear concentration range for 5-HT was 3.5 × 10(-9) -5.1 × 10(-3) mol/L, with a detection limit of 5 × 10(-10) mol/L. The relative standard deviations (RSDs) of the ECL intensity and the migration times for six continuous injections of 1.0 µmol/L 5-HT were 2.48% and 1.3%, respectively. The method was successfully applied to 5-HT assay in samples of human serum in 5 min and the extraction recoveries with spiked serum samples were over 94.4%.