牛乳中黄曲霉毒素B_1和M_1检测方法的比较

比较了免疫亲和柱-高效液相色谱法(HPLC)和酶联免疫吸附法(ELISA)测定牛乳中黄曲霉毒素B1(AFB1)和M1(AFM1)的回收率、方法检出限及精密度。结果表明,HPLC法测定AFB1、AFM1的检测限分别为0.02和0.01μg·L-1,ELISA法测定AFB1、AFM1的最低检出限分别为0.05和0.02μg·L-1;阴性牛乳试样AFB1(0.003、0.006、0.012、0.024μg·kg~(-1))和AFM1(0.005、0.01、0.025、0.05μg·kg~(-1))的回收率试验表明,HPLC法测定AFB1与AFM1的回收率分别为77.58%~82.81%和77.51%~82.23%,变异系数分别为1.93%和3.51%;ELISA法测定AFB1与AFM1回收率分别为77.28%~79.11%和75.40%~76.34%,变异系数分别为2.20%和3.80%,两种方法测定AFB1的回收率差异不显著(P0.05),当AFM1添加浓度大于0.025μg·kg~(-1)时,HPLC法回收率显著高于ELISA法(P0.05);综上,两种方法灵敏度高、重复性好,HPLC法测定高浓度AFM1时准确性优于ELISA法。

Comparison of methods for detecting aflatoxins B1 and M1 in milk

Immunoaffinity column-high performance liquid chromatography (HPLC)and enzyme-linked immu-nosorbent assay (ELISA)methods were adopted to determine aflatoxins (AF)B1 and M1 in milk.The recover-y,detection limit,and precision of these two methods were compared in this study.The results showed that, for HPLC,the detection limits of AFB1 and AFM1 were 0.02 and 0.01 μg · L-1 ,respectively,while for ELISA,the detection limits of AFB1 and AFM1 were 0.05 and 0.02μg·L-1 ,respectively.Standard solutions of AFB1 (0.003,0.006,0.012,and 0.024μg·kg-1 )and AFM1 (0.005,0.01,0.025,and 0.05μg·kg-1 )were added into blank milk samples and the results of recovery experiments indicated that,for HPLC,the recoveries of AFB1 and AFM1 were 77.58%~82.81% and 77.51%~82.23% with relative standard deviations of 1.93%and 3.51%,respectively.For ELISA,the recoveries of AFB1 and AFM1 were 77.28%~79.11% and 75.40%~76.34% with relative standard deviations of 2.20% and 3.80%,respectively.The recovery of AFB1 did not sig-nificantly differ between the two methods (P〉0.05).However,the recovery of AFM1 ,when the amount added was more than 0.025μg·kg-1 ,was significantly higher by HPLC than by ELISA (P〈0.05).In conclu-sion,both the tested methods were highly accurate,with a high sensitivity and good repeatability.At higher concentrations of AFM1 ,the accuracy of HPLC was better than that of ELISA.