水中全氟烷基醚类羧酸的超高效液相色谱-串联质谱检测方法研究

Analysis of Perfluoroalkyl Ether Carboxylic Acid in Water by Ultra-performance Liquid Chromatography-Tandem Mass Spectrometry

电喷雾离子源条件下全氟烷基醚类羧酸(PFECA)发生源内裂解和CO_(2)中性丢失,导致其准分子离子峰的丰度降低,影响该类化合物的检测灵敏度。该文选择[CF_(3)(CF_(2))_(n)O]或[M-H-CO_(2)]作为母离子,其他次级氟化烷氧基和烷基片段作为子离子,可将全氟烷基醚类羧酸的质谱响应最大提高4个数量级。结合液液萃取,对水样中4种全氟烷基醚类羧酸进行超高效液相色谱-串联质谱检测。4种PFECA均具有良好的线性关系,相关系数(r^(2))均大于0.99,检出限和定量下限分别为0.001~0.005 ng/mL和0.003~0.01 ng/mL,加标回收率为90.2%~108%,相对标准偏差(RSD)不大于7.9%。该方法为PFECA的准确定量、高灵敏检测提供了依据。

The abundance of excimer ion peaks could be decreased by the in⁃source fragmentation and neutral loss of molecule CO_(2)occurred within perfluoroalkyl ether carboxylic acids(PFECAs)under ESI source,which affects the detection sensitivity for PFECA.In this paper,[CF_(3)(CF_(2))nO]or[M-H-CO_(2)]was selected as the parent ion,and fluorinated alkoxy and alkyl groups were selected as the daughter ions,which could increase the response of PFECAs by 4 orders of magnitude at most.Four PFECAs in water samples were detected by ultraperformance liquid chromatographytandem mass spectrometry combined with liquid-liquid extraction.There were good linear relationships for the four analytes with their correlation coefficients(r2)larger than 0.99.The limits of detection and limits of quantitation were in the range of 0.001-0.005 ng/mL and 0.003-0.01 ng/mL,respectively.The spiked recoveries ranged from 90.2%to 108%,with relative standard deviations(RSD)not more than 7.9%.The method provides a platform for the accurate quantification and high sensitive detection of PFECAs.