Determination of tropane alkaloids in Przewalskia tangutica Maxim. using capillary electrophoresis with electrochemiluminescence detection

On the basis of an Eu-PB modified platinum electrode as the working electrode, a method for the simultaneous determination of the four tropane alkaloids, namely, anisodamine, scopolamine, atropine, and anisodine by capillary electrophoresis with electrochemiluminescence detection (CE-ECL) has been established. The effects of several factors, such as the detection potential, the acidity and concentration of the running buffer, and the content of the methanol additive were investigated for the improvement of separation ability and detection sensitivity. Under the optimized conditions, these four components could be fully separated from each other in a 20 mmol/L phosphate buffer (pH 8.0) containing 7% (v/v) methanol within 6 min. The relative standard deviations of the peak area and migration time were less than 5.0% and 1.1% (n = 12), respectively, for all the four compounds. This method had been successfully applied to the determination of anisodamine and scopolamine in rhizomes of Przewalskia tangutica Maxim. The average amount of anisodamine and scopolamine in the herbal rootstalk sample were 27.8 g/kg and 4.43 g/kg, respectively. The recoveries of the tropane alkaloids were 97.8%–102%.