Determination of 20 perfluoroalkyl substances in greenhouse vegetables with a modified one-step pretreatment approach coupled with ultra performance liquid chromatography tandem mass spectrometry(UPLC-MS-MS).

A new rapid modified one-step QuEChERS (quick, easy, cheap, effective, rugged, and safe) approach was developed for the simultaneous determination of 20 perfluoroalkyl substances (PFASs) from samples of cucumber, lettuce, eggplant, tomato, and leek. Several parameters were optimized. Similar pretreatment approaches were employed for comparison; the results verified the satisfactory performance of this new method. The detection limits of this method for the selected matrices ranged from 0.003 to 0.034 μg kg-1, and the method was verified to be satisfactory in terms of precision, accuracy, and matrix effects. 35 greenhouse vegetable samples were determined. PFASs were detected in 26 samples, with perfluorooctanoic acid (PFOA) being detected most frequently and much higher levels of PFBA and PFPeA being found in some samples. The total PFAS concentrations ranged from not detectable to 0.683 μg kg-1. This method could be applied for large scale determination of vegetables to research the migration and accumulation trends of PFASs from the environment to crops in the future.