【摘要】 目的建立奶粉中3-氯-丙二醇脂肪酸酯(3-MCPD酯)和2-氯-丙二醇脂肪酸酯(2-MCPD酯)气相色谱-质谱联用(GC-MS)测定方法。方法采用乙醚和石油醚提取奶粉中的脂肪,以甲醇钠-甲醇溶液水解脂肪,硅藻土小柱净化,经七氟丁酰基咪唑衍生后,采用GC-MS测定,以氘代同位素标准品为内标,内标法定量。结果 3-MCPD酯和2-MCPD酯在20~600ng范围内有良好的线性关系,相关系数(r)均>0.999;添加两个浓度水平回收,3-MCPD酯和2-MCPD酯回收率分别为91.22%~107.41%和90.26%~107.88%,相对标准偏差(RSD)分别为2.59%~4.85%、3.11%~6.34%,检出限均为0.03mg/kg,定量限均为0.10mg/kg。60份奶粉样品中,3-MCPD酯检出率为68.33%,2-MCPD检出率为18.33%。结论建立的方法灵敏度高,准确可靠,适用于奶粉中3-MCPD酯和2-MCPD酯检测;奶粉中氯丙醇酯检出率较高,存在一定的食品安全暴露风险。更多还原

【Abstract】 Objective To establish a method for determination of 3-MCPD esters and 2-MCPD esters residues in milk powders by gas chromatography-mass spectrometry.Methods Samples were extracted by aether and petroleum ether,hydrolyzed of fat with sodium methoxide-methanol and cleaned up by diatomite solid phase extraction column.After being derivatized with heptafluoro butyrylimidazole(HFBI),the analytes were determined by GC-MS,quantitatively analyzed by internal standard method using deuterium isotopes as internal standard ﹒ Results The linear relationships of 3-MCPD esters and 2-MCPD esters were good in the range of 20-600 ng,with the correlation coefficients more than 0.999.At 2 spiked levels,the recovery of 3-MCPD esters and 2-MCPD esters were 91.22%-107.41% and 90.26%-107.88%respectively,the relative standard deviations(RSDs)were 2.59%-4.85% and 3.11%-6.34%,respectively.The detection limit was 0.03 mg/kg,while the quantification limit was 0.10 mg/kg.Among 60 milk powder samples,the detection rate of 3-MCPD esters and 2-MCPD esters were68.33% and 18.33%,respectively.Conclusion The established method is highly sensitive,accurate and precise,which is suitable for the detection 3-MCPD esters and 2-MCPD esters in milk powder samples.The high detection rate of 3-MCPD esters in milk powder samples indicates certain risk of food safety exposure.更多还原