DEVELOPMENT OF A TECHNIQUE FOR CODETERMINATION OF TANNIN AND GALLIC ACID IN MEDICINAL PLANT RAW MATERIAL

摘要

Development and validation of a new technique for direct spectrophotometric quantitative determination of high- and low-molecular-mass tannins are reported. The proposed method enables simultaneous codetermination using Firordt calculations of tannins and gallic acid in medicinal plant raw material and herbal preparations without preliminary separation from complicated mixtures with other biologically active compounds found in the plant extracts. The developed method was validated (using nettle raw material as an example). The contents of gallic acid and tannins in the samples were (1.20 +/- 0.04)% and (1.52 +/- 0.03)%, respectively, which agreed with literature data.