The MS conditions were as follows: spray voltage 4000 V; capillary temperature 350 C; sheath gas
pressure (N2) 20 units; auxiliary gas pressure (N2) 5 units; collision gas (Ar) 1.5 mTorr; and scan time 0.5 s. The mass spectrometer was operated in full scan mode to identify possible degradation products of tebuconazole and in selected reaction monitoring (SRM) mode to quantify tebuconazole residues.