HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY OF ISOFLAVONOIDS AND COUMESTROL FROM HUMAN URINE

A rapid, sensitive and precise diode-array reversed-phase HPLC method was developed for human urine analysis of the most common dietary isof lavones daidzein, genistein, formononetin and biochanin-A, their mamma lian metabolites equol and O-desmethylangolensin, and of coumestrol, a nother commonly occurring phytoestrogen. Analytes were isolated and co ncentrated by solid-phase extraction and separated by HPLC followed by identification through retention times and UV scans, and in the case of coumestrol additionally by fluorometric response. This method was a pplied to monitor changes in urinary excretion of these analytes after challenge with soybeans and was evaluated for precision and recovery of analytes.