Rapid UPLC–ESI–MS/MS method for the analysis of isoflavonoids and other phenylpropanoids

UPLC–ESI–MS/MS method was developed for the quantitative and qualitative analysis of 26 phenolic compounds in plant material, including 15 isoflavonoids (daidzein, genistein, isoformononetin, formononetin, prunetin, biochanin A, daidzin, genistin, ononin, sissotrin, osajin, pomiferin), 5 flavones (apigenin, kaempferol, quercetin, quercetin-3-glucoside, rutin), 4 flavanones (hesperetin, naringenin, naringenin-7-glucoside, naringin), a coumestan (coumestrol) and a coumarine (scopoletin). The analytes were detected in a multiple reaction monitoring mode and quantified using internal standards [13C3]daidzin, [2H6]naringenin and [2H4]genistein. Limits of detection were in the range 0.001–10 pmol injection−1. The precision of the method (relative standard deviation) ranged from 2.6 to 15.1% and the accuracy was –22.1 to 16.6%. Application of the method was demonstrated by the analysis of mung bean (Vigna radiata) sprout extract, in which 14 of the 26 analytes were detected and quantified.