Separation and determination of beta-agonists in serum by capillary zone electrophoresis with amperometric detection

A simple, reliable and reproducible method, based on capillary zone electrophoresis with amperometric detection, for separation and determination of beta-agonists, namely adrenaline, salbutamol and salmeterol in serum was described in this paper. A carbon-disk electrode was used as working electrode. The optimal conditions of separation and detection were pH 6.6 phosphate buffer solution (0.06 mol/l), 12 kV for the separation voltage and 0.85 V (versus Ag/AgCl) for the detection potential. The linear ranges were from 1.0×10-7 to 1.0×10-5 mol/l for adrenaline, 3.0×10-7 to 5.0×10-5 mol/l for salbutamol, and 5.0×10-7 to 8.0×10-5 mol/l for salmeterol with the correlation coefficient of 0.998, 0.998 and 0.992, respectively. The detection limits for adrenaline, salbutamol, and salmeterol were 5.0×10-8, 2.0×10-7 and 2.0× 10-7 mol/l (based on the signal to noise ratio of 3). The method built in this paper was directly applied to the determination of beta-agonists in the spiked serum without any other sample pre-treatment except filtration, and the assay results were satisfactory.