以液相層析檢測蔬果中巨環內酯類農藥之殘留   全文下載

Simultaneous Determination of Macrolide Pesticides in Fruits and Vegetables by Liquid Chromatography

本研究係以固相萃取（Solid-phase extraction, SPE）操作，配合液相層析建立一套多重殘留之分析方法，可同時檢測6 種常見的蔬菜（芥藍、結球白菜和茄子）及水果（柳橙、木瓜和草莓）中四種巨環內酯類農藥及其代謝產物之微量殘留。利用氰甲烷及醋酸銨緩衝溶液（10 mM, pH 4.0）（90 : 10, v/v）萃取樣品中殘留農藥，以NH2 固相萃取匣作為凈化，並以逆相高效能液相層析儀及C18 分離管柱進行檢液中分析物分離，以紫外光波長250 nm 偵測之。分析方法確效試驗，標準劑添加濃度為2、20 及100 μg/mL 三種濃度（添加體積為1.5 mL，樣品相當於添加濃度分別為0.15、1.5 及7.5 μg/g），方法試驗結果，平均回收率介於75-117% 之間，相對標準偏差介於0.4-13.3% 之間。顯示本試驗方法之準確度（accuracy）及精密度（precision）均符合歐盟之農藥殘留分析品管規範（SANCO/2007/3131），即平均回收率（mean recovery） 介於70-120% 之間， 及相對標準偏差（relative standard deviation, RSD）不大於20%。方法偵測極限（method LOD）介於0.01 至0.03 μg/g 之間。本方法分析效能可靠、操作簡易有效率，可用時檢測農產品中四種巨環內酯類農藥及其代謝產物。"

A multiresidue method was developed and validated for the determination of four macrolide pesticides (spinosad, emamectin benzoate, abamectin and milbemectin) and their metabolites in six kinds of vegetables and fruits (Chinese kale, cabbage, eggplant, orange, papaya and strawberry). The pesticide residues were extracted from the samples with acetonitrile/10 mM aqueous ammonium acetate (NH4OAc), pH 4.0 (90:10, v/v) and the purification was carried out with an aminopropyl (NH2) solid-phase extraction cartridge. Reversed-phase high-performance liquid chromatograpy (RP-HPLC) using an ODS-AM column 5 μm, where a gradient elution with methanol/acetonitrile/10 mM aqueous NH4OAc, pH 4.0 mobile phase was employed for the separation and quantification of the pesticides. The method accuracy and precision were determined via recovery experiments and four replicates spiked with three fortification levels (0.15, 1.5, 7.5 μg/g) each. From the overall results of analytes, method LOD values were ranged from 0.01 to 0.03 μg/g, the mean recoveries were in the range of 75-117% and the relative standard deviations (RSD) were lower than 14%. The recovery data from six sample matrices met the acceptability criteria (European Union, SANCO/2007/3131) of recovery (70-120%) and RSD (＜20%) at the three levels studied. The simple and efficient method with acceptable performance was thus established for the simultaneous determination of four macrolide pesticides and their metabolites in agricultural products.