氟化衍生-固相萃取对水中痕量膦酸的GC-MS检测

Combination of perfluorinated derivatization and solid phase extraction for the determinationof methyl phosphonic acid in water by GC/MS

针对水中痕量(<1 mg/L)甲基膦酸类化合物进行了GC-MS定性分析检测研究。建立了固相萃取结合氟化物衍生的方法进行样品制备。采用600MHz核磁对氟化物衍生效率进行分析,衍生效率大于99%。采用气相色谱-电子轰击电离质谱(GC-EI/MS)、气相色谱-化学源负电离质谱(GC-NCI/MS)以及气相色谱-选择离子扫描质谱(GC-SIM-MS)分析方法对5种标准物质沙林、梭曼原体以及甲基膦酸异丙酯、甲基膦酸乙酯、甲基膦酸的衍生化产物进行了分析,检出限分别为10,50,0.2,0.1,0.05μg/L,方法的相对标准偏差小于7%。

In this paper, trace amounts of methyl phosphonic acid compound （ 〈 1mg/L） in water was qualitatively analyzed by gas chromatograph-mass spectrometry （GC/MS）. The 600MHz NMR was used to evaluate the pentafluorobenzoyl derivatization efficiency, which could reach up to 99%. The GB, GD and the derivatization product of IMPA, EMPA and MPA were analyzed by gas chromatography-electron ionization/mass spectrometry （GC-EI/MS）, gas chromatography-negative chemical ionization/mass spectrometry （GC-NCI/MS） and gas chromatography-selective ion monitoring-mass spectrometry （GC-SIM-MS）. The limits of detection for the GB, GD, EMPA, IMPA and MPA were 10, 50, 0. 2, 0. 1 and 0.05 μg/L, respectively. The relative standard deviation of the five reference compounds were below 7%. The real sample was measured by GC-SIM-MS after perfluorinated derivatization. By comparing the spectra of standard and real samples, the trace amount of additives was obtained. This detection method showed a significant specificity for methyl phosphonic acid compounds.