大米样品经甲醇-10 mmol·L-1磷酸溶液(70+30)提取,提取液稀释过滤后经Citri TestTM免疫亲和柱层析净化后用高效液相色谱法测定其桔霉素的含量.以Kromasil 100-10 C18色谱柱(250 mm×4.6 mm,5 μm)为分离柱,甲酸(1+99)溶液与乙腈以体积比1比1混合的溶液作流动相,采用荧光检测,激发波长为350 nm,发射波长为500 nm.必要时采用液相色谱-串联质谱法对结果作验证.桔霉素的质量浓度在5.0~500.0 μg·L-1范围内与其峰面积呈线性关系,测定下限(10S/N)为10.0 μg·kg-1.方法的回收率为73%~76%,相对标准偏差(n=8)为7.5%~11.8%.

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.