Abstract:

Based on an Eu-PB modified platinum electrode as the working electrode, a method for the simultaneous determination of the four tropane alkaloids, 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 (pH 8.0) containing 7% (v/v) methanol buffer 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. Thus, the method has been successfully applied to the determination of anisodamine, scopolamine in Przewalskia tangutica Maxim. The average amounts of 27.8 g/kg anisodamine and 4.43 g/kg scopolamine were found in the herbal rootstalk sample. The recoveries of the tropane alkaloids were 97.8%-102%.

Key words: chemically modified electrode, electrochemiluminescence (ECL) detection, Przewalskia tangutica Maxim. , tropane alkaloids, capillary electrophoresis (CE)