A MICROBORE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY METHOD FOR THE DETERMINATION OF THE PHYTOESTROGENS GENISTEIN AND DAIDZEIN IN COMMINUTED BABY FOODS AND SOYA FLOUR

A microbore high performance liquid chromatographic/electrospray/mass spectrometric (HPLC/ESI-MS) method has been developed for the determin ation of the phytoestrogens daidzein and genistein in soya flours and baby foods, The samples were hydrolysed and extracted with acetonitril e-water prior bo analysis. LC: was performed on a microbore Primespher e 5C8 column using a water/acetonitrile/acetic acid mobile phase at a flow rate of 60 mu l/min. Atmospheric pressure ionization in the form of pneumatically assisted electrospray spray mass Spectrometry (ESI-MS ) was used as the method of detection, The limit of detection was 0.2 mg/ kg for daidzein and 0.7 mg/kg for genistein in the flour and food samples. The method proved both robust and reliable when operated over a long time period (10 days, 463 injections) generating precision dat a with a coefficient of variation of 4-15%. (C) Crown Copyright.