DEVELOPMENT AND VALIDATION OF AN ISOCRATIC HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR QUANTITATIVE-DETERMINATION OF PHYTOESTROGENS IN SOYA BEAN

High-performance liquid chromatography (HPLC) is the technique most of ten used for the separation and quantification of phytoestrogens in va rious plants and food products. A number of HPLC methods using gradien t elution have been developed for determination of phytoestrogens. The se HPLC methods have been applied to the separation and quantification of phytoestrogens in various sample matrices. However, gradient eluti on methods are time consuming as they necessitate lengthy equilibratio n times and they require specialised pumps. This paper describes the d evelopment and validation of a reversed-phase HPLC method with isocrat ic conditions for the analysis of daidzein, genistein and biochanin A in soya beans using flavone as an internal standard. The proposed meth od has an overall elution time of about 24 min which compares well wit h elution times of 20-60 min for the gradient methods. Results for the linearity, sensitivity, precision and accuracy of the method are pres ented. (C) 1998 Elsevier Science B.V.