超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法同时测定血清中12种全氟化合物

Determination of 12 perfluoroalkyl substances in human serum by UPLC-Q-Orbitrap HRMS

[背景]全氟化合物(PFAS)是一类具有潜在健康风险的新型持久性有机污染物,建立生物样本中PFAS的检测方法,对评估人群暴露负荷和健康效应具有重要意义。[目的]利用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法,建立同时测定人血清中6种全氟羧酸类化合物(全氟庚酸、全氟辛酸、全氟壬酸、全氟癸酸、全氟十一烷酸、全氟十二烷酸)、5种全氟磺酸类化合物(全氟丁基磺酸、全氟己基磺酸、全氟庚基磺酸、全氟辛基磺酸、全氟癸基磺酸)和1种全氟磺酰胺类化合物(全氟辛基磺酰胺)质量浓度的方法。[方法]比较3种固相萃取柱(ProElut PLS柱、Oasis HLB柱和Supelclean ENVI-18柱)对PFAS的保留能力,4种不同比例甲醇淋洗液和3种洗脱液(甲醇、乙腈及异丙醇)对固相萃取回收率的影响以及流动相中乙酸铵缓冲盐浓度对峰形的影响。通过增加预分离色谱柱消除背景值,用同位素内标法定量,将10倍信噪比浓度定义为方法的定量限。以加标回收率评价方法的准确度,日内和日间相对标准偏差评价方法的精密度。将所建立的方法应用于20份脐带血清样本的检测,以观察其应用效果。[结果]Oasis HLB柱以30%(体积分数)甲醇为淋洗液,异丙醇为洗脱液时可以获得较好的回收率(39%~103%)。目标物以含有5 mmol·L^(-1)乙酸铵的水-甲醇体系为流动相,用C18色谱柱分离,可以获得较好的色谱峰形和质谱响应。12种目标物校准曲线线性范围为0.01~10.00μg·L^(-1)(其中:全氟庚酸和全氟辛基磺酸为0.10~10.00μg·L^(-1),全氟癸基磺酸和全氟辛基磺酰胺为0.05~10.00μg·L^(-1));方法定量限为0.01~0.10μg·L^(-1),加标回收率在81.0%~123.7%之间,日内和日间精密度分别为1.2%~14.8%和0.4%~16.1%。PFAS在20份实际样品中均有检出,9种PFAS的检出率为100%。[结论]建立的方法具有线性范围宽,检出限低,可同时检测多种待测物等优点,各方法学指标均能满足生物监测中快速、准确、同时测定血清中多种PFAS的需求。

[Background]Perfluoroalkyl substances(PFAS)are a novel type of persistent organic pollutants with potential human health effects.To establish a method for determination of PFAS in biological samples is of great significance for both exposure and health risk assessments.[Objective]This methodological study aims to establish an ultra-high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry(UPLC-Q-Orbitrap HRMS)method for simultaneous determination of 6 perfluorinated carboxylic acids(perfluoroheptanoic acid,perfluorooctanoic acid,perfluorononanoic acid,perfluorodecanoic acid,perfluoroundecanoic acid,and perfluorododecanoic acid),5 perfluorosulfonic acids(perfluorobutane sulfonate,perfluorohexane sulfonate,perfluoroheptane sulfonate,perfluorooctane sulfonate,and perfluorodecane sulfonate),and 1 perfluoralkyl sulfonicacid(perfluorooctane sulfonamide)in human serum.[Methods]Three solid phase extraction(SPE)columns,namely ProElut PLS,Oasis HLB,and Supelclean ENVI-18,were compared for their retention of PFAS.To obtain a better extraction recovery rate,methanol wash solutions with four different fractions and three eluents(acetonitrile,methanol,and isopropanol)were tested.Ammonium acetate buffer salt was added to improve the peak shape.A pre-separation column was used to reduce background noise.PFAS were quantified by isotopic internal standard method.The limits of quantification were determined at 10 times signal-to-noise ratio.The accuracy and precision were evaluated by recovery rate and intraand inter-day relative standard deviations.The established method was applied to 20 umbilical cord serum samples.[Results]An optimal recovery rate(39%-103%)was achieved by using Oasis HLB column,washing with 30%methanol(v/v)and eluting with isopropanol.Good peak shape and mass response were obtained by using H2O-methanol(containing 5 mmol·L^(-1)ammonium acetate)as mobile phase and C18 column as separation column.The linearity ranges of calibration curves of 12 analytes were from 0.01 to 10.00μg·L^(-1)(perfluoroheptanoic acid and perfluorooctane sulfonate:0.10-10.00μg·L^(-1);perfluorodecane sulfonate and perfluorooctane sulfonamide:0.05-10.00μg·L^(-1)),with a limit of quantification between 0.01 and 0.10μg·L^(-1).The average recoveries of the analytes in spiked serum samples ranged from 81.0%to 123.7%.The relative standard deviations of the intra-and inter-day precision were from 1.2%to 14.8%and from 0.4%to 16.1%,respectively.PFAS were detected in all the 20 serum samples,and 9 kinds of PFAS were 100%detectable.[Conclusion]The established method is featured with good linearity and a low limit of detection.Various methodological indicators show that the method can be applied to the simultaneous determination of multiple PFAS in serum samples accurately and rapidly.