[Determination of salbutamol sulfate in medicaments by capillary electrophoresis with contactless conductivity detection].

A method for the determination of salbutamol sulfate in medicaments by capillary electrophoresis with contactless conductivity detection has been developed. The effects of several important factors, such as nonaqueous and aqueous solvents, background electrolyte and its concentration as well as the pH, separation voltage, sample injection time, excitation voltage and excitation frequency, were investigated. The optimized separation conditions were as follows: the running buffer was an aqueous solution (pH 2.7) containing 15 mmol/L lactic acid, the separation voltage was 10 kV, the electrokinetic injection time was 3 s at 10 kV, the excitation voltage was 60 V, and the excitation frequency was 120 kHz. The results have shown that there was a linear relationship (r = 0.995) between the response of the peak area and the mass concentration of salbutamol sulfate in the range from 9.60 to 48.0 mg/L, and the limits of detection (S/N = 3) was 1.92 mg/L. The relative standard deviation for the migration time of salbutamol sulfate was 2.7%. The method has been successfully applied in the determination of the contents in the tablet and aerosol of salbutamol sulfate, separately. The results were in accordance with the values marked by the pharmaceutical industry. Moreover, the recoveries were 90% - 113%. This simple and quick analytical method can be used for determining salbutamol sulfate.