全氟辛酸和全氟辛烷磺酸异构体的膳食暴露来源

Dietary sources of human exposure to perfluorooctanoic acid,perfluorooctanesulfonate and their isomers

本研究采用超高效液相色谱串联三重四级杆质谱法测定了福建省当地居民血清和总膳食样品中全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)典型异构体的污染水平,并分析了血清和膳食中PFOA和PFOS支链/直链的比例,初步探讨了当地居民支链PFOA和PFOS的膳食暴露来源.结果表明,在所有血清样品中均可检出n-PFOA和n-PFOS,其中位数浓度水平分别为3.7 ng·mL^(-1)和7.0 ng·mL^(-1),且血清中检出了5种PFOS支链异构体和1种PFOA支链异构体.血清中n-PFOA占total-PFOA的比例(99.81%)和n-PFOS占total-PFOS的比例(84.56%)均显著高于目前市场上销售的PFOA和PFOS工业品.而对于膳食样品,仅在乳类膳食中检出2种支链PFOA异构体,未在膳食样品中检出PFOS支链异构体.血清和膳食样品中不同的支链/直链PFOA和PFOS的比例对比结果表明:乳类膳食有可能是福建省居民暴露于支链PFOA异构体(br-PFOA)的重要来源,支链PFOS异构体(br-PFOS)可能存在膳食暴露之外的重要暴露途径.

Levels of PFOA,PFOS and their isomers in the serum and the total diet study（TDS）samples from Fujian were detected by ultra-performance liquid chromatography coupled with tandem mass spectrometry.The percentage and the dietary source of human exposure to the branched/linear isomers of PFOA and PFOS were analyzed.n-PFOA and n-PFOS were detected in any serum sample,with the median concentration of 3.7 ng·mL^-1 and 7.0 ng·mL^-1,respectively.Five branched isomers of PFOS were detected,and only one branched isomer of PFOA was detected in the serum.The percentage of n-PFOA to total-PFOA（99.81%） and n-PFOS to total-PFOS（84.56%） in serum were significantly higher than that in PFOA and PFOS industrial products.And two branched isomers of PFOA were detected in the milk samples,whereas no branched isomers of PFOS were detected in any diet sample.The results of the comparison of the percentage of branched/linear isomers of PFOA and PFOS between serum and diet samples indicated that the intake of milkmay be an important source of human exposure to br-PFOA.In addition to diet intake,there may be other important sources of human exposure to br-PFOS.