DETERMINATION OF ISOFLAVONES BY CAPILLARY ELECTROPHORESIS ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY

The qualitative and quantitative determination of several isoflavone n atural products is described using combined capillary electrophoresis/ electrospray ionization mass spectrometry. Negative-ion electrospray i onization has been shown to be a suitable technique for the analysis o f these compounds. Although low sample lending is a drawback to the CE technique, coupling CE with MS overcomes the problem and utilizes the mass-resolving capability and high sensitivity of the spectrometer fo r structural analysis of the mixture. Quantitative analysis of synthet ic mixtures was carried out using calibration graphs for injections in the range 0.2-20 fmol and had correlation coefficients of 0.997 and 0 .994 for pseudobaptigenin and daidzein, respectively.