基质辅助激光解析电离飞行时间质谱方法测定全氟烷基磺酸类化合物

Determination of perfluoroalkyl sulfonic acid compounds by matrix-assisted laser desorption ionization time of flight mass spectrometry

以α-氰基-4-羟基肉桂酸(α-cyano-4-hydroxycinnamic acid,HCCA)、2,5-二羟基苯甲酸、芥子酸3种常用基质作为基质,分析5种全氟烷基磺酸(全氟丁烷磺酸、全氟己烷磺酸、全氟庚烷磺酸、全氟辛烷磺酸、全氟癸烷磺酸)的基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption ionization time of flight mass spectrometry,MALDI-TOF MS)信号,建立全氟烷基磺酸类化合物的MALDI-TOF MS快速检测方法,初步探究常用基质在负离子反射模式下产生的质谱峰及对待测物的干扰,为全氟烷基磺酸化合物MALDI-TOF MS定量分析及高通量检测方法的建立打下基础。以HCCA作为基质,建立了全氟辛烷磺酸的内标定量检测方法,解决了MALDI-TOF MS检测中定量难的问题。该研究结果表明,采用MALDI-TOF MS内标法测定水中全氟辛烷磺酸的重复性和灵敏度良好,在质量浓度为5~500 ng/mL时,线性相关系数R^(2)为0.9979,检出限为1 ng/mL,定量限为5 ng/mL,水样加标回收率为65%~106%,相对标准偏差为2.36%~17.7%,应用该方法检测水中的全氟辛烷磺酸,能有效实现环境水样中全氟辛烷磺酸的快速定量分析。

A matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF MS)was developed for the rapid detection of perfluoroalkyl sulfonic acid compounds.MALDI-TOF MS signals of five kinds of perfluorobutane sulfonic acid were ana-lyzed usingα-cyano-4-hydroxycinnamic acid(HCCA),2,5-dihydroxybenzoic acid(DHB)and sinapinic acid(SA)as a matrix.The spectrum produced by common matrix in negative ion reflection mode and the interference to analytes were investigated.An internal stand-ard quantitative determination method for PFOS was established using HCCA as a matrix,which solved the problem of difficult quantitative determination in MALDI-TOF MS.Results showed that the MALDI-TOF MS internal standard method had good repeatability and sensitivi-ty for the determination of PFOS in water.The linear correlation coefficient R^(2) was 0.9979 in the concentration range of 5-500 ng/mL,the recovery rate of water samples was 65%to 106%,and the relative standard deviation(RSD)ranged from 2.36%to 17.7%.This method can be used to detect perfluorooctanesulfonic acid(PFOS)in water,and can effectively realize the rapid quantitative analysis of PFOS in environmental water samples.