【摘要】 目的建立油炸食品中氯丙醇酯(包括3-MCPD酯和2-MCPD酯)固相萃取同位素稀释气相色谱-质谱(GC-MS)检测方法,并分析油炸食品中氯丙醇酯水平。方法在超市、早餐店和街头早餐点采集油炸食品88份,以未检出氯丙醇酯的油炸食品作为空白样品。样品采用溶剂浸提法提取出脂肪,脂肪以甲醇钠-甲醇溶液进行酯键断裂反应,以硅藻土小柱进行固相支持液液萃取净化,净化液经七氟丁酰基咪唑衍生后进行GC-MS检测,以氘代同位素标准品为内标进行内标法定量。采用空白样品的加标回收率评价方法的准确度,以回收率的相对标准偏差(RSD)评价方法的精密度。结果 3-MCPD酯和2-MCPD酯在25~1 000μg/L浓度范围线性关系良好,相关系数(r)均>0.999 5。3-MCPD酯、2-MCPD酯的检出限均为20μg/kg。空白样品的脂肪提取物在25、50、100、200μg/kg水平的加标回收率在89.7%~110.0%之间,RSD均<8.4%。88份样品中3-MCPD酯和2-MCPD酯检出率分别为81.82%和70.45%,含量范围分别为未检出(ND)~1.65 mg/kg和ND~0.93 mg/kg。结论该方法适用于油炸食品中氯丙醇酯含量的测定;油炸食品氯丙醇酯污染较为普遍。更多还原

【Abstract】 Objective To establish an isotope dilution gas chromatography-mass spectrometry(GC-MS) for the determination of chloropropanol esters in fried foods.Methods A total of 88 fried food samples were collected from supermarket,breakfast shop and street breakfast,stalls,the fried food sample with no chloropropanols esters detected was used as the blank sample.Samples were extracted using a solvent extraction method,followed by ester-bond cleavage reaction with sodium methylate-methanol and purification by diatomite solid-supported liquid-liquid extraction column.The derivatives in purified solution was detected by GC-MS after being derivatived with heptafluoro butyrylimidazole.The concentration of chloropropanols esters was quantified by using deuterium isotopes as internal standards.The accuracy of the method for evaluating recovery rate of blank samples was adopted,and the relative standard deviation(RSD) of the recovery rate represents the precision of the method.Results The 3-MCPD ester and 2-MCPD ester had good linear relationship in the concentration range of 25-1 000 g/L(r>0.9995).The detection limits of 3-MCPD ester and 2-MCPD ester were 20 μg/kg.The recovery rate of fat extracts from blank samples at 25,50,100,and 200 μg/kg levels ranged from 89.7% to 103.7%,and RSD<8.4%.The detection rates of 3-MCPD ester and 2-MCPD ester in 88 samples were81.82% and 70.45% respectively,and the content ranges from not-detected(ND) to 1.65 mg/kg and to 0.93 mg/kg respectively.Conclusion The method is simple,accurate and reliable.It is suitable for the determination of chloropropanol esters in fried foods.There is a certain degree of contamination of chloropropanol esters in fried foods,and this comtamination is quite common.更多还原