title: Quantitative detection of trace perfluorinated compounds in environmental water samples by Matrix-assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry with 1,8-bis(tetramethylguanidino)-naphthalene as matrix.
abstract: Determination of perfluorinated compounds (PFCs) is very important because of their potential hazards to the environment and human health. In present work, 1,8-bis (tetramethylguanidino)-naphthalene (TMGN), a superbasic proton sponge, was firstly employed as the matrix for quantitative detection of acidic PFCs in environmental water samples by Matrix-assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS). Several acidic PFCs, such as perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), were selected as model analytes for demonstrating the feasibility of the detection method. The results showed that deprotonated ions of these PFCs were detected without any other matrix ions interference. The achieved sensitivity with TMGN for PFOS detection was ten-fold higher than that with 1,8-bis (dimethyl-amino)-naphthalene (DMAN) which was used for the detection of fatty acid by MALDI-TOF-MS. The high sensitivity of this method made it feasible to monitor and quantify acidic PFCs in complicated environmental water samples. Furthermore, a novel combined strategy of solid phase extraction (SPE) followed by MALDI-TOF-MS detection was developed for quantifying PFCs in environmental water samples. The calibration curves with a wide linear dynamic range (0.1-10 ng L(-1) for PFOS, PFHxS, and PFBS, and 0.5-50 ng L(-1) for PFOA, PFNA, and PFDA.) were obtained. The limit of detection (LOD) for PFOS of this method was 0.015 ng L(-1) (a signal-to-noise ratio of 3), which was lower than the LOD (0.036 ng L(-1)) obtained by high-pressure liquid chromatography/tandem mass spectrometry (LC-MS/MS) method. Moreover, the strategy was used to detect the selected PFCs in water samples collected from Xiaoqinghe river and Gaobeidian wastewater. The achieved concentrations of PFCs were closed to those obtained by LC-MS/MS method. It is indicated that the proposed MALDI-TOF-MS method with TMGN as the matrix is much reliable and can be used as an alternative method to detect trace PFCs in environmental water samples.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, P.O. Box 2871, 18 Shuangqing Road, Haidian District, Beijing 100085, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Cao
authors.forename: Zhidong
authors.initials: Z
authors.lastname: Wang
authors.forename: Chunguang
authors.initials: C
authors.lastname: Han
authors.forename: Lin
authors.initials: L
authors.lastname: Cui
authors.forename: Ming
authors.initials: M
authors.lastname: Hu
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wu
authors.forename: Yongxue
authors.initials: Y
authors.lastname: Liu
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Cai
authors.forename: Hailin
authors.initials: H
authors.lastname: Wang
authors.forename: Yuehui
authors.initials: Y
authors.lastname: Kang
mesh_terms: D002138:Calibration; D004784:Environmental Monitoring / Q000379:methods*; D005466:Fluorocarbons / Q000032:analysis*; D057230:Limit of Detection; D009281:Naphthalenes; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods* / Q000592:standards; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005466:Fluorocarbons; D009281:Naphthalenes; D014874:Water Pollutants, Chemical