- 期刊
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Dissipation of the fungicide azoxystrobin in Brassica vegetables
殺菌劑亞托敏在包葉菜及小葉菜之殘留消退分析
摘要
Residues of the fungicide azoxystrobin applied to vegetables according to the recommended procedures were studied. Two applications of azoxystrobin, formulated as a 23% suspension concentrate, were applied to Chinese cabbage (Brassica pekinensis Rupr.) and a leafy vegetable (Chinese kale, B. alboglabra). Samples were collected at 0, 3, 6, 9, 12, 15, 18, and 21 d after the last application and were extracted into acetonitrile: water (9:1 v/v). An aliquot of the extract was partitioned with dichloromethane and cleaned-up through a silica column. Residues of azoxystrobin were determined using reversed-phase high performance liquid chromatography with ultraviolet absorption at 255 nm. The limit of detection was 0.02 mg/kg. Recoveries of azoxystrobin from Chinese cabbage and kale were 84.9% and 86.1%, respectively. Results showed that residues of azoxystrobin on Chinese cabbage declined from 4.10 to 0.63 mg/kg within 18 d, and from 13.21 to 0.10 mg/kg within 9 d on Chinese kale. The residue limit of azoxystrobin was respectively established as 2 and 1 mg/kg for Chinese cabbage and kale (as a proxy for leafy vegetables) in Taiwan. The safe harvest intervals were suggested to be 15 and 10 d after the last application for Chinese cabbage and leafy vegetables, respectively.
並列摘要
本研究依據亞托敏殺菌劑在田間推薦之施藥方法，進行其在包葉菜及小葉菜之殘留消退分析。針對包心白菜（Brassica pekinensis Rupr.）及芥籃菜（B. alboglabra），分別噴灑2次23%亞托敏水懸劑。依序於最後一次施藥後之0、3、6、9、12、15、18及21天採樣，樣品經腈甲烷:水（9/1, v/v）及silica淨化管之淨化後，以液相層析儀附255 nm波長之紫外光偵測器進行殘量分析。偵測界限可達0.02 mg/kg。亞托敏於包心白菜及芥藍菜之回收率分別為84.9%及86.1%。農藥殘留分析結果，發現包心白菜中之亞托敏殘留量於當天為4.10 mg/kg，於施藥後18天，有0.63 mg/kg之殘留；而在芥藍菜之殘留量於當天為13.21 mg/kg，但施藥後9天，亞托敏之殘留量已降至0.10 mg/kg。目前訂定亞托敏在葉菜類之容許量為2 mg/kg（包葉菜）及1 mg/kg（小葉菜），因此建議其安全採收期分別為15天（包葉菜）及10天（小葉菜）。