A method for determination of 9 isoflavones in Puerariae Lobatae Radix was established and the accuracy and feasibility of the method were verified. The relative correction factors of eight isoflavonoids,3'-hydroxy puerarin,puerarinapioside,3'-methoxy puerarin,puerarin 6″-O-xyloside,daidzin,genistin,formononetin and daidzein were determined by HPLC method with puerarin as the internal standard. The contents of 9 isoflavonoids in 11 batches of samples were determined by external standard method and QAMS.The accuracy and feasibility of the methods were evaluated by comparison of the quantitative results between external standard method and QAMS. The reproducibility of the relative correction factors was good under different experimental conditions,and there was no significant difference between the external standard method of the 9 compounds and the content of QAMS method. The results showed that using puerarin as an internal standard to simultaneously determine the 8 isoflavonoids mentioned above is accurate and feasible. Thus,it can be used as quality control of Puerariae Lobatae Radix.
Keywords: Puerariae Lobatae Radix; QMAS; correction factor; external standard method; isoflavonoids.