Determination of perfluoroalkyl carboxylic acids in environmental water samples by dispersive liquid–liquid microextraction with GC-MS analysis

Abstract

The present study focused on developing a rapid, efficient, and eco-friendly method for the analysis of perfluoroalkyl carboxylic acids (PFCAs) in aqueous matrices. The proposed method was based on esterification of PFCAs by isobutyl chloroformate followed by dispersive liquid–liquid microextraction (DLLME) of the derivatives. Quantitation of the isobutyl esters of PFCAs was carried out by gas chromatography-mass spectrometry with electron ionization. Under the optimal conditions, PFCAs could be determined in linear ranges of 1–1000 ng mL−1 with good correlation coefficients (r > 0.991). The limits of detection and limits of quantification ranged from 0.9 − 3.0 ng mL−1 and 2.7 − 9.0 ng mL−1, respectively. The method showed satisfactory reproducibility with intra-day and inter-day relative standard deviations (RSDs) in the range of 3.4 − 14.6% and 3.5 − 17.2%, respectively. It was successfully applied to determine PFCAs in several river and lake waters, ranging from 8.47 to 150.14 ng mL−1.