冷冻-离心净化-高效液相色谱法测定植物油中黄曲霉毒素B1

Determination of Aflatoxin B1 in Vegetables Oil by Freeze-Centrifugation Purification and HPLC

通过冷冻-离心净化,建立了高效液相色谱定量测定植物油中黄曲霉毒素B1的方法,并将其用于测定市场上30批植物油产品中黄曲霉毒素B1的含量。以水/乙腈溶液为提取剂对植物油中黄曲霉毒素B1进行萃取,低温冷冻固化植物油,冷冻离心使植物油和提取液分离、净化提取液,经衍生后上液相色谱进行定量分析。优化的乙腈/水提取液配比为90∶10,低温冰箱冷冻温度为-12℃,冷冻离心转速为12 000 r/min、离心力约为1.4万×g,以水浴加热的方式进行衍生。方法的定量检出限为0.02μg/kg,校准曲线回归方程为y=2.321 987x+0.001 377,相关系数(R2)为0.999 7,在0.10~5.0μg/L范围内线性关系良好。当样品中黄曲霉毒素B1添加量为0.5、1.0、5.0μg/kg时,平均回收率为80.2%~93.2%,相对标准偏差为2.9%~4.7%(n=6),均优于免疫亲和柱净化处理的结果。市售植物油产品中黄曲霉毒素B1的浓度范围为<LOD至5.72 μg/kg,均低于GB 2761-2017中对该指标的限值,花生油和玉米油中黄曲霉毒素B1均有检出,油茶籽油和核桃油中黄曲霉毒素B1均低于检出限。该方法样品前处理简便、稳定性好、检出限低,适合植物油中黄曲霉毒素B1的批量检测。

In this study, a method for quantitative determination of aflatoxin B1 in vegetable oil was established by freeze-centrifugation purification and high performance liquid chromatography. Moreover, it was used to determine the content of aflatoxin B1 in 30 batches of vegetable oil products from the market. In this method, the aflatoxin B1 in vegetable oil was extracted with water/acetonitrile solution;and the oil by freezing and centrifugation further removed;after derivatization, liquid chromatography was used for quantitative analysis. The optimized acetonitrile/water extract ratio is 90∶10, the freezing temperature is-12 ℃, the freezing centrifugal speed is 12 000 r/min, the centrifugal force is about 14 000×g, and it is derived by water bath heating. The quantitative detection limit of the method was 0.02 μg/kg, the regression equation of the calibration curve was y=2.321 987x+0.001 377, the correlation coefficient(R2) was 0.999 7, and the linear relationship was good in the range of 0.10~5.0 μg/L. When the amount of aflatoxin B1 added in the sample was 0.5, 1.0, 5.0 μg/kg, the average recovery was 80.2%~93.2%, and the relative standard deviation was 2.9%~4.7%(n=6), which was better than immunoaffinity column purification treatment. The concentration of aflatoxin B1 in commercially available vegetable oil products ranges from <LOD to 5-72μg/kg,both lower than the limitation regulated by GB 2761-2017-Both aflatoxin B1 in peanut oil and corn oil were detected,and aflatoxin B1 in camellia seed oil and walnut oil were lower than the detection limit.This method has the advantages of simple sample preparation,stableness and low detection limit,and is suitable for batch detection of aflatoxin B1 in vegetable oil.