School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Chinese Academy of Inspection and Quarantine, Beijing 100176, China.
Chinese Academy of Inspection and Quarantine, Beijing 100176, China.
Talanta. 2020 Aug 1;215:120929. doi: 10.1016/j.talanta.2020.120929. Epub 2020 Mar 13.
The present study reports the first conception to incorporate a non-polar solvent, dichloromethane, as the spray solution in easy ambient sonic-spray ionization (EASI) for mass spectrometry (MS) analysis of hydrophobic compounds. An imidazolium-based dicationic ionic liquid (DIL) at a low concentration of 20 μM was used in combination with dichloromethane. A reactive EASI strategy was implemented, by which the overall positively charged associated complexes of anionized perfluorinated compounds (PFCs) were formed in the presence of the DIL. In positive ionization mode, 19- and 6-fold enhancements in signal intensity were witnessed for the analysis of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) respectively, compared to that in negative ionization mode with no dicationic ion-pairing reagent. The limits of detection (LODs) and quantitation (LOQs) are 0.5 and 0.8 μg/m for PFOA and 0.4 and 0.6 μg/m for PFOS, respectively. The developed method allowed direct ambient analysis of samples in their native conditions and was applied to the analysis of PFCs in a variety of real textile, popcorn bucket, and oil-proof hamburger wrapping paper samples.
本研究首次报告了将非极性溶剂二氯甲烷纳入简易环境超声喷雾电离（EASI）中，用于对疏水性化合物进行质谱（MS）分析。在 20 μM 的低浓度下，使用基于咪唑鎓的二阳离子离子液体（DIL）与二氯甲烷结合。采用反应性 EASI 策略，在 DIL 的存在下形成阴离子化全氟化合物（PFC）的整体带正电荷的缔合配合物。在正离子化模式下，与负离子化模式下没有二阳离子离子对试剂相比，分别对全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）的分析得到了 19 倍和 6 倍的信号强度增强。检出限（LOD）和定量限（LOQ）分别为 0.5 和 0.8 μg/m 对于 PFOA 和 0.4 和 0.6 μg/m 对于 PFOS。所开发的方法允许直接在其天然状态下对样品进行环境分析，并应用于各种实际的纺织品、爆米花桶和防油汉堡包装纸样品中的 PFC 分析。
