HPLC Determination of Citrinin in Rice with Purification by Immunoafinity Chromatography

Citrinin was extracted from rice sample with a mixture of methanol and 10 mmol·L-1 phosphoric acid (70+30),and the extract obtained was diluted and purified by passing through the immoumoaffinity chromatographic column Citri TestTM column. In the HPLC analysis,Kromasil 100-10 C18 column (250 mm×4.6 mm,5 μm) was used as separation column,and a solution of dil. formic acid (1+99) and acetonitrile mixed in the ratio of 1 to 1 by volume was used as mobile phase. Fluorescence detection at wavelengths of (λex) 350 nm and (λem) 500 nm was adopted in the determination. Results were confirmed if necessary by hyphenation of LC-MS/MS. Linear relationship between values of peak area and mass concentration of citrinin was obtained in the range from 5.0 to 500.0 μg·L-1,with lower determination limit (10S/N) of 10.0 μg·kg-1. Values of recovery and RSD′s (n=8) of the method were found in the range of 73%-76% and 7.5%-11.8%,respectively.