Detection of the potential adulterant Teucrium chamaedrys in Scutellaria baicalensis raw material and extract by high-performance thin-layer chromatography.

Teucrium chamaedrys (Gemander) has been reported as an adulterant of Scutellaria lateriflora (American skullcap) herbal preparations and is also known to be hepatotoxic. A quick and simple high-performance thin-layer chromatographic (HPTLC) method was developed for the detection of T. chamaedrys (Germander) in S. baicalensis (Chinese skullcap) extract, an ingredient of the proprietary blend product, Univestin. The HPTLC profile of T. chamaedrys was distinguished from that of S. baicalensis by its bright green fluorescence bands. This simple method can be completed in an hour for the quality control of Univestin and its raw material, S. baicalensis. The method is sensitive and can detect T. chamaedrys at levels as low as 0.5% (w/w).

Product-specific sample clean-up and HPLC analysis of aflatoxins for a dietary product.

INTRODUCTION: A sample clean-up procedure has been developed for a complex dietary ingredient, Unigen Inc. (Lacey, WA, USA) product A (a proprietary mixture of Scutellaria baicalensis and Acacia catechu extracts), for the determination of aflatoxins by HPLC. OBJECTIVE: To develop an appropriate sample specific clean-up procedure that removes interferences from the sample for the determination of total aflatoxins B(1), B(2), G(1) and G(2) at or lower than 20 ppb by HPLC. METHODOLOGY: The sample specific clean-up procedure was developed based on the modification of AOAC method 990.33. RESULTS: Coextract interferences were removed with the clean-up procedure. The recovery of total aflatoxins was 70% with RSD about 2%; the LOD and LOQ were 1.6 and 5.2 ppb, respectively, for total aflatoxins; the linearity R(2) > 0.99. None of the samples tested showed the presence of detectable aflatoxins. CONCLUSION: The modified clean-up method was effective to remove coextract interferences from Unigen product A samples.