[Determination of the content of benzoic acid in Sanguis Draconis of qili san by TLCS].

The Content of benzoic acid in Sanguis Draconis of Qili San was Determined by thin layer chromatography in order to control the quality of Sanguis draconis. The results have shown that this determination is a simple accurate method, and can be used as a standard for the quality control of Qili San.