Rapid Determination of Clonidine in Starch by Capillary Electrophoresis

A method for the rapid determination of clonidine in starch by capillary electrophoresis (CE) was proposed. A mixture of phosphoric acid and 25 mmol·L-1 sodium dihydrogen phosphate solution of pH 2.2 was used as background electrolyte, and separation voltage of 20 kV was applied. UV-detection at the wavelength of 214 nm was adopted. Under the optimized conditions, linear relationship between values of corrected peak area and mass concentration of clonidine was obtained in the range of 0.3 to 200 mg·L-1, with detection limit (3S/N) and lower limit of determination (10S/N) of 0.1 mg·L-1and 0.3 mg·L-1 respectively. Recovery and precision of the method were tested by standard addition method, the results of recovery found were in the range of 97.1 %-98.4 % and RSD′s (n=5) were less than 2.0%.