Pyrimethanil residues on table grapes Italia after field treatment.

Residues of the pyrimidine fungicide pyrimethanil [N-(4,6-dimethylpyrimidin-2yl)aniline] were determined in table grapes "Italia" by gas chromatography nitrogen-phosphorus detector (GC-NPD). Pesticides were extracted from grapes with ethyl acetate and hexane solution (1:1 v/v), and were analyzed without any further clean up. Pyrimethanil was confirmed by high-performance liquid chromatography (HPLC) fitted with a diode array detector (DAD) and electrospray ionization mass spectrometry (ESI-MS) in the select ion-monitoring mode (SIM). The residue of pyrimethanil was under the legal limit immediately after treatment, and showed a half-life time, calculated as a reaction of pseudo first order, of 12 days, with a regression coefficient of 0.9954. Recoveries from fortified grapes ranged between 90 and 113% with a maximum coefficient of variation (CV) of 11%. The calculated limits of detection and quantitation for pyrimethanil were 0.005 and 0.01 mg/kg, respectively.