Abstract: An analytical method was developed to determine citrinin in red yeast rice by liquid chromatography\|tandem mass spectrometry (LC\|MS/MS). This method was simple, sensitive, specific, and could quantitatively detect citrinin with a small amount of extraction solvent. The samples were extracted with methanol, then the extracts were separated on a chromatographic column using methanol (containing 01% formic acid and 20 mmol·L-1 ammonium acetate)∶water (90∶10, V/V) as mobile phase by gradient elution, and were finally analyzed by LC\|MS/MS in selected reaction monitoring (SRM) mode via positive electrospray ionization. The method showed good linearities in the range of 01-100 μg·kg-1 for citrinin. The recovery rates of the different spiking concentrations were in the range of 809%-1073%, with the relative standard deviation (RSD) of 20%. The detection limits (LOD) of sample was 50 μg·kg-1. The proposed method was also used to determine citrinin in 12 commercial red fermented rice products from different areas. It was shown that citrinin pollution were detected in 10 samples with the level of 014-4424 mg·kg-1.

Key words: citrinin, red fermented rice, LC\, MS/MS