Residue and dissipation of ethirimol in apple

Spraying 70% thiophanate-methyl (50%) ethirimol(20%) up in apple. Residue and dissipation of ethirimol were investigated in field. Ethirimol in the samples was extracted with acetonitrile, purified with SPE and detected by the high performance liquid chromatography (HPLC-UV) method. The results showed that when ethirimol was spayed at the 525 mg/kg, the half-life was 1.94-2.65 d in 2010, 2.07-2.70 d in 2011,respectively. When ethirimol was sprayed at 525 mg/kg four times a year, preharvest interval of ethirimol in apple set at 10 days, the final residues of ethirimol in apple were no detected 7 days after spaying the fourth time, which was lower than MRL of EU (0.1 mg/kg).