高效液相色谱-荧光法测定食用油中苯并(a)芘残留量

Determination of benzo(a)pyrene residues in edible oil by HPLC-fluorescence method

建立了高效液相色谱-荧光法测定食用油中苯并(a)芘残留量的方法。样品经正己烷提取、苯并(a)芘分子印迹柱净化后,进高效液相色谱仪,在RP-C18保护柱Welch C18色谱柱(250 mm×4.6 mm×5μm)、88%乙腈-水溶液为流动相、进样量10μL条件下,用荧光检测器(激发波长384 nm,发射波长406 nm)测定食用油中苯并(a)芘含量。结果表明:该方法的苯并(a)芘线性范围为1~10 ng/mL,相关系数为0.99991,检出限为0.2μg/kg,平均加标回收率为94.9%。采用该方法对7种市售食用油中苯并(a)芘进行测定,结果发现,玉米胚芽油、鱼油中未检出苯并(a)芘,黑芝麻油中苯并(a)芘含量为2.780μg/kg,胡麻籽油中苯并(a)芘含量为0.863μg/kg,葵花仁油中苯并(a)芘含量为0.238μg/kg,大蒜油中苯并(a)芘含量为0.410μg/kg,五味子油中苯并(a)芘含量为0.132μg/kg,均低于国家规定限量(10μg/kg)。与国标法相比,该方法操作简便,节约时间,且灵敏度高、回收率稳定,适用于多种食用油中苯并(a)芘残留量的快速检测分析。

A HPLC-fluorescence method for determination of benzo(a)pyrene(BaP)residues in edible oil was established.The sample was extracted by n-hexane,and purified by BaP molecular imprinted column,then injected into HPLC,under the conditions of RP-C18 as protective column,Welch C18(250 mm×4.6 mm×5μm)as chromatographic column,88%acetonitrile-aqueous as mobile phase,and sampling volume 10μL,the residue of BaP in edible oil was determined by fluorescence detector(excitation wavelength 384 nm,emission wavelength 406 nm).The results showed that the linear range of BaP was 1-10 ng/mL,the correlation coefficient was 0.99991,the detection limit was 0.2μg/kg,and the average standard recovery rate was 94.9%.The BaP contents of seven vegetable oils on sale were determined by the method,and it was showed that no BaP was detected in corn germ oil and fish oil.The contents of BaP in black sesame oil,flaxseed oil,sunflower seed kernel oil,garlic oil,and Schisandrae fructus oil was 2.780,0.863,0.238,0.410,0.132μg/kg respectively,which were lower than the national limit of 10μg/kg.Compared with the national standard method,this method was simple,time-saving,sensitive and stable,and were suitable for the rapid detection and analysis of BaP residues in various edible oils.