固相萃取柱净化-气相色谱法定量测定食用植物油中饱和烃类矿物油

Quantitative determination of mineral oil saturated hydrocarbons in edible vegetable oils by solid phase extraction column-gas chromatography

中文关键词:  食用植物油  饱和烃类矿物油  固相萃取  气相色谱

英文关键词:edible vegetable oil  mineral oil saturated hydrocarbons  solid phase extraction  gas chromatography

中文摘要:

      目的 以自制硫酸硅胶和10%硝酸银硅胶填料分层装填的复合固相萃取柱为净化手段, 建立一种测定食用植物油中饱和烃类矿物油的分析方法。方法 样品经正己烷提取, 固相萃取柱净化, 氮吹浓缩, 然后经DB-1石英毛细管色谱柱分离, 采用气相色谱-火焰离子化检测器检测, 外标法定量。结果 考察了填料类型、填料用量、洗脱体积等因素对提取效率的影响。在优化的条件下, 饱和烃类矿物油检测的线性范围为5.0~500.0 mg/L, 相关系数r2=0.9991, 方法检出限为3.0 mg/kg, 定量限为10.0 mg/kg。样品在10.0、20.0、50.0 mg/kg 3个水平下的加标回收率为93.2%~103.7%, 相对标准偏差为3.97%~5.33% (n=6)。结论 该法操作简单、快速、准确度高, 检出限能满足对食用植物油中饱和烃类矿物油残留的检测要求, 且使用常规分析仪器、分析成本低, 值得推广应用。

英文摘要:

      Objective To establish a gas chromatographic method for the simultaneous determination of mineral oil saturated hydrocarbons in edible vegetable oils by packing sulfuric acid silica gel and 10% silver nitrate-silica gel separately, a homemade double solid phase extraction purification column. Methods The samples were extracted by hexane, purified with solid phase extraction column, then concentrated by nitrogen, separated by the capillary columns of DB-1, determined by a flame photometric detector and quantified by external standard method. Results The effects of influencing factors on extraction efficiency were investigated, including packing type, amount of packing and elution volume. Under the optimized experimental conditions, the limits of detection and limits of quantification of this method were 3.0 mg/kg and 10.0 mg/kg. Satisfactory linearity in the ranges of 5.0~500.0 mg/L was obtained with a correlation coefficient of 0.9991. The spiked recoveries were in the range of 93.2%~103.7% at three spiked levels with the relative standard deviations (RSDs) of 3.97%~5.33% (n=6). Conclusion The established method is simple, rapid and accurate, which is suitable for the separation and quantification of mineral oil saturated hydrocarbons in edible vegetable oils. Furthermore, the homemade column is low cost and worthy of popularization and application.