Method development for analysis 13 per- and polyfluoroalkyl acids in tap water by HPLC-MS/MS

The purpose of this study was to develop a sensitive, accurate and simple method for analysis of 13 perfluoroalkyl acids (8 perfluoroalkyl carboxylic acids and 5 perfluoroalkyl sulfonic acids) in tap water by LC-MS/MS. This paper focuses on optimizing the chromatographic instrumental operating parameters and the solid phase extraction conditions using HLB cartridges. Results from the method validation showed that the method has sub ng/L LOQs (0.10-0.60 ng/L), quantitative recoveries at the concentrations near the LOQs (74.4-122.8%) and high repeatability with acceptable %RSD (15.6-38.3%). The analytical procedure was then applied to assess how significant the contamination of PFAAs in tap water of Ho Chi Minh City. Besides that, a new self-made solid phase extraction material prepared by grafting an ionic liquid on silica was used to enrich the target analytes. Preliminary results show that the material based on 1-octyl-3-(3-(triethoxysilyl) propyl)-1H-imidazolium bromide has promising retention ability for these compounds, the recoveries on ionic liquid-based materials ranged from 36.3-69.0%.