A SIMULTANEOUS DETERMINATION OF DAIDZIN AND PUERARIN AND DETERMINATION OF DAIDZEIN IN ORIENTAL PHARMACEUTICAL DECOCTIONS CONTAINING PUERARIAE RADIX BY ION-PAIR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple and precise method was established for the simultaneous deter mination of daidzin and puerarin and the determination of daidzein in oriental pharmaceutical decoctions containing Puerariae Radix using hi gh-performance liquid chromatography with tetra-n-heptylammonium bromi de (THA) as an ion-pair reagent. Daidzin and puerarin were eluted with in 45 min without interference with co-existing components using an OD S column and a mixture of 10 mm phosphate buffer (pH 6.5)-methanol (68 : 32) containing 5 mm THA as a mobile phase. Daidzein was eluted with in 35 min without interference with co-existing components using an OD S column and a mixture of 10 mm phosphate buffer (pH 6.5)-acetonitrile (72 : 28 or 68 : 32) containing 5 mm THA as a mobile phase.