Electrochemistry of sinapine and its detection in medicinal plants.

Sinapine (O-sinapoyl choline) is a crucial component, with much medicinal value, of many dietary and medicinal plants. It has been found that sinapine gives an electrochemical response at a pyrolytic graphite electrode. The electrochemical properties of sinapine have been investigated. The peak current in the cyclic voltammogram is linear in the concentration range 1.9 x 10(-6)-2.5 x 10(-4) mol L(-1) and the limit of detection is 9.9 x 10(-7) mol L(-1). These properties can be applied to the determination of sinapine in extracts from three kinds of medicinal plant. The electrochemical method reported here is highly selective, sensitive, and stable.