A fast determination of isoflavones (genistin, genistein, daidzein, daidzin, glycitin, glycitein, ononin, formononetin, sissotrin and biochanin A) by HPLC/UV-vis-DAD working at 254 nm is described. An Atlantis dC18 fast reversed-phase chromatographic column (20 mm x 2.1 mm, 3 microm particle size) was used at a flow rate 0.35 ml min(-1) of a mobile phase consisted from 0.1% (v/v) acetic acid (A) at pH 3.75 and methanol. (B). A linear gradient profile was used for separation at the column temperature 36 degrees C. Limits of detection (LODs for 3 S/N criterion) per sample injection (5 microl) ranged from 166.2 to 17.0 fmol (9.4-1.1 ng ml(-1) for biochanin A and genistin, respectively. The recoveries 96-106% were obtained for the different concentrations of the isoflavones (RSDs 2-8%). The pressurized liquid extraction/HPLC/UV-vis-DAD method was used for the determination of the isoflavones in soy bits (28-962 microg g(-1) dry weight). The proposed procedure is faster (ca. 8 min) without loosing its separation efficiency (up to 10 isoflavonoids can be determined) and sensitivity (tens to hundreds fmol).

Department of Chemistry and Biochemistry Mendel University of Agriculture and Forestry Zemedelská 1 CZ 613 00 Brno Czech Republic

References provided by Crossref.org

Effect of five different stages of ripening on chemical compounds in medlar (Mespilus germanica L.)

Fully automated spectrometric protocols for determination of antioxidant activity: advantages and disadvantages

Use of liquid chromatography with electrochemical detection for the determination of antioxidants in less common fruits