小黃瓜經殺菌劑白克列 50% 水分散性粒劑噴施後之殘留分析   全文下載

Residue Analysis of Fungicide Boscalid in Cucumbers Following Applications of Boscalid 50% Water Dispersible Granule

本研究以殺菌劑白克列50% 水分散性粒劑進行小黃瓜田之噴藥試驗，於小黃瓜田噴施三次後，進行小黃瓜果實上之殘留消退分析。噴灑濃度分別為0.5及0.83 kg a.i./ha。於最後一次噴灑後之第0、1、2、3、4、6、7、10、12、15、18及21天採收小黃瓜。將10 g樣品與50 ml 甲醇：純水:2 n 鹽酸（70:25:5，v/v）以均質機均質1分鐘，以10% 氯化鈉水溶液將部分萃取液洗至分液漏斗，再經50 ml正己烷液液萃取15 min，將收集之有機層經無水硫酸鈉脫水、濃縮後，以正己烷定量並以氣相層析儀附電子補獲式偵測器及dB-5毛細層析管進行白克列之殘留分析。白克列於小黃瓜之回收率範圍為86.0-103.6%（rSd為1.2-4.8%），定量之偵測極限為0.01 μg/ml（S/n >10）。以此分析方法應用於田間施藥後小黃瓜之殘留消退分析，結果顯示小黃瓜果實上之白克列殘留隨時間而消退，以前述二種噴灑濃度於最後一次施藥後之第6天，小黃瓜果實上白克列之殘留僅剩最初殘留之5和17%。

This study determined the residue of fungicide boscalid in/on cucumbers following three applications of boscalid 50% water dispersible granule (WG). The fungicide was applied to cucumbers at two rates, 0.5 and 0.83 kg a.i./ha. Samples were collected at 0, 1, 2, 3, 4, 6, 7, 10, 12, 15, 18, and 21 d after the last application. The sample was extracted with methanol/H2O/2 N HCl (70:25:5, v/v) and n-hexane and subject to GC analysis. Residues of boscalid were determined by GC/μ-ECD with DB-5 capillary column. Recoveries of boscalid in/on cucumbers ranged from 86.0 to 103.6% and the relative standard deviation (RSD) ranged from 1.2 to 4.8%. The limit of quantification was 0.01 μg/mL (S/N>10). This analytical method was applied to study the dissipation of boscalid in/on cucumbers. The results indicated that the residues of boscalid were declined in/on cucumbers with time. Only 5 and 17% of the initial deposits were found in/on the cucumbers 6 d after the last application at the low and high dose, respectively.