目的 建立食品中脂肪酸氯丙醇酯(3-MCPD酯、2-MCPD酯)自动索氏提取-气相色谱-质谱法检测方法。方法 食品中的脂肪经自动索氏提取仪提取后与甲醇钠－甲醇溶液发生碱水解反应,硅藻土基质固相分散萃取柱净化,七氟丁酰基咪唑(HFBI)衍生后用GC-MS法检测脂肪酸氯丙醇酯,以氘代同位素标准品为内标,内标法定量。结果 3-MCPD酯、2-MCPD酯的量为0.2～6 mg/kg时,GC-MS方法线性关系良好,相关系数(r)﹥0.9990,3-MCPD 酯、2-MCPD酯的检出限均为30 μg /kg;在花生油样品中添加0.9 mg/kg时,3-MCPD酯、2-MCPD酯的回收率分别为93.4%和94.7% ,相对标准偏差(RSD)分别为2.7%和3.2%。结论 自动索式提取-GC-MS方法简便、准确、可靠,适用于含脂肪食品及食用植物油中氯丙醇脂肪酸酯含量的测定。

Objective To establish a method for determination of fatty acid esters of chloropropanols(3-MCPD esters, 2-MCPD esters) in foods by automatic soxhlet extraction-gas chromatography- mass spectrometry (GC-MS). Methods The fat samples react with sodium methylate-methanol and the solution purified by solid phase extraction column. After derivation with heptafluoro butyrylimidazole( HFBI), the analytes were determined by GC-MS and quantified by the deuterated internal standards. Results Method to extract fat from foods was highly efficient. Good linearities of the GC-MS method were obtained from 3-MCPD esters, 2 -MCPD esters within 20 ng-600 ng, with coefficient correlations(r)>0.9990. The limits of detection( LODs) for 3-MCPD esters, 2-MCPD esters were 30μg/kg. The recoveries of 3-MCPD esters, 2-MCPD esters at 0.9 mg/kg in peanut oil were 93.4% and 94.7%, with relative standard deviations(RSD) 2.7% and 3.2%. Conclusion This method is simple, accurate and reliable, which is suitable for the determination of fatty acid esters of chloropropanols in foods.