SPE-GC-FID法检测食品包装纸中的矿物油
Determination of mineral oil in food packaging paper by solid phase extraction- gas chromatographyflame ionization detector
-
摘要: 建立了食品包装纸中矿物油的固相萃取-气相色谱分析方法。以正己烷∶乙醇(v/v,1∶1)为提取溶剂,对浸泡法、超声波和微波辅助提取三种提取方法进行比较和优化,提取液经硝酸银硅胶柱分离纯化,采用气相色谱法对食品纸包装材料中的矿物油进行定量。结果表明:采用超声波辅助提取法,提取时间20 min,提取次数2次,温度30℃,料液比(w∶v)1∶10效果最好。石蜡油在20500 mg/L的浓度范围内,线性良好,相关系数为0.9996,方法的检出限和定量限分别为2.57 mg/L和7.79 mg/L,加标回收率为79.0%86.5%,相对标准偏差(RSD)小于5.0%,日内和日间精密度(RSD)均小于3.0%。应用此方法对六类食品包装纸中的矿物油进行检测,饼干外包装纸的矿物油含量最高,测定的矿物油含量在160.86104.9 mg/kg之间。该方法灵敏,定量准确,操作简单,可用于食品包装纸中矿物油的检测。Abstract: The solid phase extraction- gas chromatography flame ionizationdetector was developed for determination of mineral oil in food packaging paper. N- hexane / ethanol( 1 ∶ 1,v / v) as the extraction solvent,the immersion,ultrasonic and microwave assisted extraction method were compared and optimized. Extract was purified by silver nitrate silica gel column; mineral oil of food materials was determinated with GC- FID.The results showed that the optimum for ultrasonic extraction: extraction time 20 min,temperature 30 ℃,extraction times 2 and solid to liquid ratio 1∶10.The calibration curve of paraffin oil was linear in the range of 20~500 mg / Lwith correlation coefficient 0.9996.Thelimit of detection and the limit of quantitation were 2.57 mg / L and 7.79 mg / L,respectively.And therecoverieswere between 79.0% and 86.5%,with relative standard deviation( RSD) less than 5.0%,the RSD of intra- day and inter- day were less than 3.0%.Finally,the method was applied in the determination of mineral oil in six kinds of food packaging paper,it revealed that mineral oil of food packaging paper used in biscuits was the highest; the content of mineral oil was between 160.8 and 6104.9 mg / kg. The method was sensitive,accuracy andrapid,which was suitable for determining mineral oil in food packaging paper.