Trace determination of alkyl methylphosphonic acids in environmental and biological samples using gas chromatography/negative-ion chemical ionization mass spectrometry and tandem mass spectrometry
作者:Sten-Åke Fredriksson、Lars-Gunnar Hammarström、Liselott Henriksson、Hans-Åke Lakso
DOI:10.1002/jms.1190300810
日期:1995.8
Alkyl methylphosphonic acids (AMPA) are metabolites and primary hydrolysis products of the organophosphorus nerve agents listed in the Chemical Weapons Convention (CWC). Gas chromatography/negative-ion chemical ionization mass spectrometry and tandem mass spectrometry (GC/NICI-MS and GC/NICI-MS/MS) were used for the determination of AMPA as their pentafluorobenzyl esters. Extremely high sensitivity was obtained and low attogram amounts could be detected by GC/NICI-MS. Ion-exchange chromatography was employed for selective isolation and enrichment of AMPA in serum, urine, water and soil samples. Collision-induced dissociation (CID) of the single methylphosphonate anion peak from NICI of the pentafluorobenzyl ester produced fragment ions specific for the methylphosphonate structure, allowing positive identification of AMPA. CID conditions optimized for structure information and for sensitivity were investigated. The improved selectivity of GC/MS/MS allows the detection of femtogram amounts of AMPA in samples where chemical background inhibits detection by GC/MS.
烷基甲基膦酸(AMPA)是《化学武器公约》(CWC)所列有机磷神经毒剂的代谢产物和主要水解产物。气相色谱法/负离子化学电离质谱法和串联质谱法(GC/NICI-MS和GC/NICI-MS/MS)用于测定AMPA的五氟苄酯。GC/NICI-MS具有极高的灵敏度,可以检测到低阿戈克的含量。离子交换色谱法用于选择性分离和富集血清、尿液、水和土壤样品中的AMPA。五氟苄酯NICI中单个甲基膦酸阴离子峰的碰撞诱导解离(CID)产生了甲基膦酸结构特有的碎片离子,从而可以正确定性AMPA。研究人员对CID条件进行了优化,以获得结构信息和灵敏度。GC/MS/MS的改进选择性使其能够在化学背景抑制GC/MS检测的样品中检测到AMPA的飞克克含量。