鸡蛋中氟虫腈及其代谢物残留分布研究

Analysis of fipronil and metabolites residues distrubution in eggs

目的 对比蛋清与蛋黄中氟虫腈及其代谢物的残留分布差异，并对加热前后生熟样品中氟虫腈及其代谢物的含量变化进行研究，以应对不同年龄段人群、不同方式食用鸡蛋摄入氟虫腈及其代谢物残留的风险评估。方法 取10枚含氟虫腈残留的鸡蛋样品，分离蛋清和蛋黄，样品经乙腈提取和净化后采用液相色谱-高分辨质谱检测，以BEH C18色谱柱为分析柱，乙腈-0.1%乙酸溶液作为流动相进行梯度洗脱分离，外标法定量。采用Full Scan/ddms2扫描模式，以负离子采集进行定性筛查和定量分析。结果 氟虫腈砜为鸡蛋中检出的氟虫腈主要残留物；蛋清中氟虫腈砜含量在2.5~59.9 μg/kg之间，中位数为16.1 μg/kg；蛋黄中氟虫腈砜含量在81.5~1 526.0 μg/kg之间，中位数为390.0 μg/kg。以蛋黄和蛋清质量折算，蛋黄/蛋清中氟虫腈砜的总量比在8.0~14.6之间。与生蛋的结果相比，蛋黄加热前后氟虫腈砜熟样/生样含量比在0.80~0.96之间，中位数为0.90；蛋清加热前后氟虫腈砜熟样/生样含量比在0.65~1.06之间，中位数为0.83。鸡蛋与蛋黄中氟虫腈砜含量的换算系数f为3.1。结论 蛋黄为氟虫腈及其代谢物摄入的主要来源，加热蒸煮对鸡蛋中氟虫腈砜的残留量无明显变化。

Objective To compare the residual distribution of fipronil and its metabolites in white and yellow egg, and to analyze the residual changes of fipronil and its metabolites in raw and cooked samples, regarding the risk assessment of fipronil and its metabolites via consuming egg for different age groups.Methods The white egg and yellow egg were isolated from 10 egg samples containing fipronil residues. Samples were extracted with acetonitrile and purified, and determined by liquid chromatography-high resolution mass spectrometry. The chromatographic analysis was performed on a BEH C18 column with 0.1% acetic acid and acetonitrile as mobile phase with gradient elution, and external standard calibration was used for quantification. The negative ion acquisition mode was applied and quantitative analysis was carried out by using Full Scan/ddms2 model.Results The results showed that fipronil sulfone was the main residue detected in eggs; The content of fipronil sulfone in white egg was between 2.5 and 59.9 μg/kg, the median was 16.1 μg/kg; and the content of fipronil sulfone in yellow egg ranged from 81.5 and 1 526.0 μg/kg, with a median of 390.0 μg/kg. The ratio of fipronil sulfone in yellow egg to white egg ranged from 8.0 and 14.6. Compared with that observed in fresh egg, after heating or cooking, the content ratio of fipronil sulfone residue between cooked samples and raw samples from yellow egg was between 0.80 and 0.96, the median was 0.90; and the ratio from white egg ranged from 0.65 to 1.06, the median was 0.83. The conversion coefficient of fipronil sulfone （f） between white egg and yellow egg was 3.1.Conclusion Yellow egg is a major intake source of fipronil and metabolites residues, and there is no obvious change for fipronil sulfone residue in eggs after heating or cooking. The conversion coefficient of fipronil sulfone （f） between white egg and yellow egg lays the foundation for assessing the health risks of fipronil and metabolites residues through yellow egg intake in special population.