Simultaneous Determination of 20 Polyfluoroalkane Substances in Dietary Milk by QuEChERS Combined with On-Line Interference Trapping LC-MS/MS Technique

This application note describes a sensitive and reliable method for determination of 20 polyfluoroalkane substances (PFASs) in milk based on the work published by Yu, et al. previously [1]. The milk sample was initially extracted and cleaned up using an optimized QuEChERS protocol, followed by an online interference trapping LC-MS/MS analysis. Using stable isotope labeled internal standards for calibration, the linear dynamic ranges for 20 PFASs were determined within 3–4 orders of magnitude, with correlation coefficients ¡0.997. The LOQs for the two types of PFASs, perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonic acids (PFSAs), were 0.010 μg/L and 0.050 μg/L, respectively. The average recoveries at three spiking levels for all compounds ranged from 72.8% to 111% with the RSD (n = 6) within 1.20–14.9%. The developed method is sensitive and reliable, thus can be applied to real sample survey.