尿液中12种全氟化合物的固相萃取-超高效液相色谱串联四极杆线性离子阱质谱分析方法研究

Study on the Analytical Method of Solid Phase Extraction-Ultra Performance Liquid Chromatography Tandem Quadrupole Linear Ion Trap Mass Spectrometry for 12 Perfluorinated Compounds in Human Urine

目的建立超高效液相色谱串联四极杆线性离子阱质谱同时测定尿液中12种全氟化合物(PFCs)的方法。方法尿样经2%甲酸调节pH后,用WAX柱萃取净化浓缩,收集洗脱液氮吹,10 mmol/L乙酸铵-甲醇(V水∶V甲=70∶30)复溶,离心取上清液进样分析。超高效液相色谱采用甲醇和10 mmol/L乙酸铵水溶液在C18柱上梯度洗脱进行分离,质谱采用多反应监测,内标法定量。结果方法在线性范围内线性良好,检出限和定量限分别为0.032~6.5 n g/L和0.10~21 ng/L。12种PFCs的加标回收率为91.5%~114%,日内精密度和日间精密度分别为0.57%~16.0%和1.88%~20.1%。将建立的方法应用于某地小学生尿液的测定,可检出9种PFCs,其中全氟丁烷磺酸和全氟辛酸为当地学生尿样的主要组成部分。结论建立的方法可同时测定尿液中12种全氟化合物,方法结合固相萃取和同位素内标校正,得到了良好的灵敏度和准确度。

Objective To establish a method for simultaneous determination of 12 kinds of perfluorinated compounds(PFCs)in human urine based on ultra performance liquid chromatography tandem quadrupole linear ion trap mass spectrometry(UPLC-QTtrap-MS).Methods After pH adjustment with 2%formic acid,the urine samples were loaded on a WAX solid phase extraction(SPE)cartridge for extraction,purification and concentration.The eluates were collected,concentrated to dryness under nitrogen,and reconstituted with 10 mmol/L ammonium acetate aqueous solution-methanol(Vwater∶Vmethanol=70∶30)before injection.UPLC was performed on a C18 cartridge,and methanol and 10 mmol/L ammonium acetate aqueous solution was used as mobile phases with gradient elution.QTtrap-MS was operated in multiple reaction monitoring(MRM)mode,and the internal standard calibration curves were applied for quantitative analysis.Results Good linearity was obtained in the linear range,with the method detection limits and method quantification limits being 0.032 ng/L-6.5 ng/L and 0.10 ng/L-21 ng/L,respectively,for the 12 kinds of PFCs.The spiked recoveries of the 12 kinds of PFCs were 91.5%-114%,with the intra-day precision and the inter-day precision being 0.57%-16.0%and 1.88%-20.1%,respectively.The established method was applied to the determination of 12 kinds of PFCs in the urine samples of primary school students collected in one area.Nine kinds of PFCs were detected in the urine samples in this area.Among the PFCs detected,perfluorobutanesulfonic acid(PFBS)and perfluorooctanoic acid(PFOA)were the main PFCs found in the student urine samples.Conclusion The method established in this study could be used to simultaneously examine 12 kinds of PFCs in urine.The method combined SPE with isotope internal standard correction and achieved good sensitivity and accuracy.