顶空–气相色谱法测定芝麻和茶叶中环氧乙烷的残留量

Determination of Ethylene Oxide Residue in Sesame and Tea by Headspace Gas Chromatography

环氧乙烷常用于食品杀菌剂,且极易在食品中造成残留,目前我国暂无可用于食品中环氧乙烷含量测定的相关标准。为解决进出口食品中环氧乙烷残留量测定问题,建立了顶空–气相色谱法测定食品中环氧乙烷的残留量的快速方法。对芝麻、茶叶等食品基质中环氧乙烷的提取条件参数进行正交优化,结果表明:使用二甲基乙酰胺溶剂超声提取方法最佳,提取温度对环氧乙烷的回收率影响最为显著,超声功率和时间次之,最佳提取条件为温度40℃,超声功率200 W,时间30 min,回收率最高为89.25%。使用HP-PLOTQ气相色谱柱,在载气最佳流速为2 mL/min时环氧乙烷的分离效果最好,且峰形对称无拖尾。在方法测定条件下,环氧乙烷在0.01~1.0mg/L浓度范围内线性良好,相关系数为0.999,相对标准偏差RSD≤2.96%,总体回收率介于76.9%~91.6%之间,能够满足食品中环氧乙烷含量检测的要求。该方法实验流程简单,可快速对食品中的环氧乙烷进行检测及定量。

Ethylene oxide is often used as a food bactericide and is easy to cause residues in food. At present,there is no relevant standard for the determination of ethylene oxide content in food in China. To solve the problem of determining ethylene oxide residues in imported and exported foods, a method for the determination of ethylene oxide residues in different kinds of food was established by headspace gas chromatography. The extraction conditions and parameters of ethylene oxide were optimized by orthogonal design, and it has found that the ultrasonic extraction method with dimethylacetamide was the best. The extraction temperature had the most significant effect on the recovery of ethylene oxide, followed by ultrasonic power and time. The optimum extraction conditions were 40 ℃ of the temperature, the 200 W of the ultrasonic power and 30 min of the time. Under this condition, the recovery was the highest up to 89.25%. Using HP-PLOTQ Column, the separation effect of ethylene oxide was the best when the flow rate of carrier gas was 2 m L/min. Under the determination conditions of this method, the linearity of ethylene oxide was good in the concentration range of 0.01~1.0 mg/L, and the correlation coefficient was 0.999. The relative standard deviation was lower than 2.96 and the overall recovery was between 76.9% and 91.6%. All these results suggested that, this method has met the requirements for the detection of ethylene oxide content in food. This method is the first time used to determin the ethylene oxide in food by headspace gas chromatography. The experimental process is si mple and can quickly detect and quantify ethylene oxide in food.