红腐乳中桔霉素的HPLC-FLD分析方法研究

建立了一种检测红腐乳中桔霉素的高效液相色谱-荧光检测（HPLC-FLD）定量分析方法.比较了不同萃取剂、料液比、提取温度、超声波处理时间、提取次数对桔霉素提取效果的影响.采用ODS WondaSil C18（150mm×4.6mmi.d.,5μm）色谱柱,体积比为45∶55的乙腈与0.03％磷酸水溶液为流动相,荧光检测器检测,波长λex为331 nm,λem为500 nm,在此条件下进行检测.结果表明：采用甲苯-乙酸乙酯-甲酸体积比为1∶9∶1的复合萃取剂,以料液比为1∶15在60℃下超声提取10 min,提取3次可将桔霉素提取完全.在桔霉素质量浓度为0.5～1 000μg/L时,桔霉素质量浓度与荧光检测器响应值呈良好线性关系（R2=0.999 9）,该方法的检出限为0.5μg/L,重复实验的RSD为1.58％,样品平均加标回收率为94％.本方法可用于红腐乳产品中桔霉素的定量分析检测.

Determination of Citrinin Content in Red Sofu by HPLC

A high performance liquid chromatography （HPLC） method for determination of citrinin in red sofu was developed. The effects of different factors including extracting solvent, material-liquid ratio, extraction temperature, ultrasonic extraction time, and extraction times on the extraction of citrinin were compared. The chromatographic separations was carried on a ODS WondaSil C1s （ 150 mm×4.6mmi.d.,5μm） column by using acetonitrile and 0.03% phosphoric acid（45： 55, v/v） , and then was detected by a fluorescence detector at Aex = 331 nm, Aem = 500 nm. The results showed that citrinin was completely extracted by toluene-ethyl acetate- formic acid（ 1：9：1 ,v/v/v） at material-liquid ratio of 1：15 （v/v） , ultrasonic extraction 10 min at 60 ℃ for 3 repeated extractions. There was a good linear relationship between the fluorescence detection values and citrinin contents in the range of 0.5 - 1 000 μg/L （R： = 0. 999 9）. The minimum detectable content of citrinin was 0.5 μg/L. The RSD of repeated test was 1.58%. The average recovery with standard was 94%. This method could be used for determining the citrinin content in red sofu products.