Determination of perfluorocarboxylic acids in water by ion-pair dispersive liquid–liquid microextraction and gas chromatography–tandem mass spectrometry with injection port derivatization

A novel technique for derivatization in a gas chromatograph injection port after a one-step extraction of trace perfluorocarboxylic acids (PFCAs) in water with ion pair formation during dispersive liquid–liquid microextraction (DLLME) was investigated. Tetrabutylammonium hydrogen sulfate (TBAHS) was used as the ion pair reagent. PFCA butyl ester derivatives were formed in the GC injection port and then analyzed using gas chromatography coupled to tandem mass spectrometry with negative chemical ionization. According to our analysis, the operative linear range for PFCA detection from 250 pg mL−1 to 2 μg mL−1 with a relative standard derivation (RSD) below 13%. Detection limits were achieved at the level of 37–51 pg mL−1. This method was successfully applied for the analyzing of PFCAs in river water samples from urban and industrial areas without tedious pretreatment. The concentration range over which PFCAs were detected is from 0.6 ng mL−1 to 604.9 ng mL−1.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► One-step extraction of perfluorocarboxylic acids in aqueous was investigated. ► Quantitation was performed by using GC–NCI-MS/MS. ► The detection limits were picogram per milliliter level for all PFCAs analyses.