Abstract:

The detection method for perfluorinated compounds (PFASs) and the sample pretreatment process for complex environments were optimized using solid-phase extraction in conjunction with ultra-high performance liquid chromatography–tandem mass spectrometry. This optimized method allowed concurrent extraction and identification of 41 PFASs in diverse environmental matrices. Optimal ion pairs and mass spectrometry parameters for the targets were determined through manual tuning of single standards for instrument optimization. The optimal chromatographic mobile phase was identified as a combination of 2 mmol/L ammonium acetate solution and methanol. Higher recovery rates and shorter extraction times compared to accelerated solvent extraction in the context of sample extraction and purification were found for ultrasonic extraction of solid samples at 30°C for 10 minutes. The use of a parallel quantitative concentrator for nitrogen evaporation resulted in an average recovery rate of 104.3%, with a process time half as long as the time required for the traditional water bath method. The average recovery rates were 108.2% and 105.5% when using 2 mmol/L ammonium acetate solution (pH = 3) and 1 mL of 0.5% ammonia methanol solution for solid-phase extraction column elution and washing, respectively. The optimized method was applied to actual samples (soil, sediment, and water), achieving detection limits of 0.01 ~ 0.34 ng, matrix spiking recovery rates of 67.9% ~ 174.9%, and relative standard deviations for parallel samples of 0.03% ~ 28.10%. Overall, the optimized sample preparation method is more time- and solvent-efficient than previous methods, offers better sensitivity and recovery rates, and thus provides a solid technical foundation for large-scale environmental sample detection.

Key words: perfluoroalkyl substances, environmental multi-media, detection methods, method application