Fig. 2.

Main sample preparation and instrumental analysis methods for the determination of isoflavones and their related compounds. Abbreviations: UAE ultrasound-assisted extraction, SFE supercritical fluid extraction, LLE liquid-liquid extraction, SLE solid-liquid extraction, SPME solid-phase micro-extraction, SPE solid-phase extraction (incorporating the Quechers approach), MAE microwave-assisted extraction, MSPD matrix solid-phase dispersion, CCC counter-current chromatography, LC liquid chromatography (HPLC high-performance liquid chromatography, UPLC ultra-performance liquid chromatography, and UHPLC ultra high-performance liquid chromatography), GC gas chromatography, MS mass spectrometry, UV ultra-violet, DAD diode array detector (also called photodiode array detector, PDA), FLD fluorescence detector, NMR nuclear magnetic resonance, ED electrochemical detection, ECD electron capture detection, FID flame ionization detection, TLC thin layer chromatography, CE capillary electrophoresis, ELISA enzyme-linked immunosorbent assay, RIA radioimmunoassay, and TR-FIA time-resolved fluorescence immunoassay