利用改进的胶束电动毛细管色谱法和液相色谱法测定6类重点食品中的脱氢乙酸

改进了实验室建立的测定脱氢乙酸的胶束电动毛细管色谱(MEKC)和国标的液相色谱(LC)的分离及样品前处理方法. 改进后的两种方法均能准确测定6类重点食品中的脱氢乙酸，为重新评估脱氢乙酸的风险、修订或制定其在不同食品中的限量标准提供依据. 改进后的MEKC和LC方法的检出限及定量限分别为0.2、0.5 mg/L和0.05、0.2 mg/L. 6类重点食品空白基质的加标回收率均在81.9%~116.0%之间，相对标准偏差在0.4%~7.3%之间. 测定了284件食品样品，结果均无超标. 使用改进的两种方法同时测定了45件样品，对其中20件阳性样品的结果进行了比较，结果吻合. 改进后的MEKC及LC方法样品前处理简单，非常适合大量样品检测.

Application of Improved Micellar Electrokinetic Capillary Chromatographic and Liquid Chromatographic Method for Determination of Dehydroacetic Acid in Six Species Key Foods

The electrophoretic, chromatographic and sample pretreatment conditions for the previously established micellar electrokinetic capillary chromatographic method (MEKC) in our laboratory and the liquid chromatographic (LC) method of the national standard were improved for the analysis of dehydroacetic acid (DHA). DHA in six species key foods could be accurately assayed by both of the two improved MEKC and LC methods. The analytical results could provide a basis for reassessing the risk of DHA and revising or resetting the permitted levels of DHA in six species key foods. The limits of detection and quantitation for the improved MEKC and LC method were 0.2, 0.5 mg/L and 0.05, 0.2 mg/L, respectively. The recoveries of the spiked blank samples of the six species key foods were in the ranges of 81.9%~116.0% with relative standard deviations ranging from 0.4% to 7.3%. 284 food samples were analyzed by the improved MEKC method. None of them exceeds the permitted levels. Forty-five samples were determined simultaneously by the two improved methods. The results of 20 positive samples were compared which were in agreement with each other. Both improved LC and MEKC methods have the advantages of simple sample pretreatment, which is suitable for routine analysis.