매실 중 살균제 azoxystrobin과 difenoconazole의 생산단계 잔류허용기준 설정

Abstract

This study was carried out to investigate the residual characteristics of fungicide azoxystrobin and difenoconazole in Prunus mume fruits, and establish pre-harvest residue limits (PHRL) based on dissipation and biological half-lives of fungicide residues. The fungicides were sprayed onto the crop at recommended dosage once and 3 times in 7 days interval, respectively. The samples were harvested at 0, 1, 2, 4, 6, 8, 10, 12 and 14 days after treatment. These residual pesticides were extracted with QuEChERS method, clean-up with NH2 SPE cartridge, and residues were analyzed by HPLC/DAD and GLC/ECD, respectively. Method quantitative limits (MQL) of azoxystrobin were 0.03 mg kg and of difenoconazole were 0.006 mg kg. Average recovery were 93.2 ± 2.49%, 85.5 ± 1.97% for azoxystrobin at fortification levels at 0.3 and 1.5 mg kg, and 100.8 ± 6.74%, 87.6 ± 9.92% for difenoconazole at fortification levels at 0.06 and 0.3 mg kg, respectively. The biological half-lives of azoxystrobin were 5.9 and 5.2 days at recommended dosage once and 3 times in 7 days interval, respectively. The biological half-lives of difenoconazole were 9.3 and 8.0 days at recommended dosage once and 3 times in 7 days interval, respectively. The PHRL of azoxystrobin and difenoconazole were recommended as 5.32 and 1.64 mg kg for 10 days before harvest, respectively.