Finally, each supernatant was passed through a 0.22-µm nylon syringe filter into a 1.5-mL glass vial for subsequent HPLC-coupled tandem mass spectrometry (MS/MS) analysis. NEO content in samples was assessed with a II HPLC (Aijiren, USA) interfaced with an Aijiren 6470 triple-quadrupole mass spectrometer system in the