火锅底料中石蜡检测的样品前处理研究

Research on the sample pretreatment methods of the paraffin in bottom material of chafing dish by GC

建立一种用于检测火锅底料中掺杂石蜡的气相色谱分析样品前处理方法。样品经石油醚直接提取,浓缩过氧化铝小柱除油,再浓缩定容后,进气相色谱分离检测。通过对9种主要正构烷烃的测定,可以定性地鉴别是否掺杂石蜡。该方法检出限为1g/kg,平均回收率为97.6%～110.0%,相对标准偏差(RSD)为2.4%～6.9%(n=6)。石蜡在1～100g/kg内呈良好的线性关系,线性回归系数r均大于0.9985。与目前报道的前处理方法比较,它在保证准确定性、定量的同时,具有前处理耗时少、处理简单、适用性强等优点。

To establish a sample pretreatment method, which is correct, sensitive, and suit- able for the determination of adulterated paraffin in Bottom Material of Chafing Dish. After extracted from the sample with petroleum ether, the analytes were chromatographically analyzed on a GC. Whether the paraffin was adulterated could be qualitatively identified via the 9 n-alkanes. The correlation coefficients were all more than 0.9985. The detection limits were lg/kg for 9 n-alkanes. The recoveries were 97.6%-110.0% and the relative standard deviations were 2,4%-6.9%（n=6）for 9 n-alkanes in a concentration range of 1-100 g/kg.The processing method compared with the reported method, while guaranteeing the accuracy qualitative and quantitative, has the proving time reduced in the pretreatment, applicability and other characteristics.