Development of a method using QuEChERS and LC-MS/MS for analysis of per- and polyfluoroalkyl substances in rice...

Detection of per- and polyfluoroalkyl substances (PFAS) in food is crucial for ensuring food safety. Therefore, we combined a quick, easy, cheap, rugged, and safe (QuEChERS) extraction method with liquid chromatography-triple-quadrupole mass spectrometry (LC-MS/MS) to detect 35 PFAS in rice. The solvents (water and acetonitrile) were adjusted to pH 2.4, a mixture of anhydrous MgSO₄, NaCl, and NaOAc was used for extraction, and anhydrous MgSO₄, a primary/secondary amine, and graphitized carbon black were applied for purification. The limits of detection and recovery were 0.005-0.100 ng·g^-1 and 86.5 %-126.4 %, respectively. When this method was used to detect PFAS in packaged instant rice cooked in a microwave or boiled in water, the microwaved sample showed a lower PFAS content. However, both samples had PFAS contents within WHO guidelines and were safe for consumption. This method can be extended to detect PFAS levels in other foods exposed to packaging materials containing PFAS.