[Determination of sulfur dioxide in traditional Chinese medicine by alkaline solution extraction and ion chromatography].

Objective: An ion chromatographic method was developed to analyze sulfur dioxide in traditional Chinese medicine (TCM).

Method: The samples were extracted with alkaline solution and reacted with formaldehyde to form hydroxymethyl sulfonic acid. The extracts were cleaned by C18 column and SO3(2-) was determined with ion chromatography equipped with a conductance detector.