Comparison of extraction methods for analysis of citrinin in red fermented rice

There is no standard method for the extraction and analysis of citrinin in red fermented rice (RFR). In the study, five extraction methods were compared for their efficiency to analyse citrinin in RFR by HPLC–FLD (reversed phase high performance liquid chromatography with fluorescence detection), including, (1) ultrasonic extraction with EW solution (ethanol:water, 7:3, v/v); (2) ultrasonic extraction with TEF solvent mixtures (toluene:ethyl acetate:formic acid, 7:3:1, v/v); (3) shaking extraction with EW; (4) shaking extraction with EF solvent mixtures (ethyl acetate:formic acid, 1:1, v/v); (5) shaking combined with ultrasonic extraction in EW. Comparison of chromatograms of citrinin by HPLC–FLD with different extraction methods revealed that EW was the best extraction solvent. It was also found that shaking combined with ultrasonic extraction in EW was the most efficient extraction method to extract citrinin from RFR for qualitative and quantitative analysis.