英文摘要 |
For regulatory monitoring of pesticides in environmental matrices, a multiresidue analysis through solid phase extraction (SPE) technique and using gas chromatographic determination of organochlorine(OC), organophosphorus(OP) and synthetic pyrethroid pesticides residues in beef fat was studied. The group of pesticides was added to dissolved beef fat (0.5 g) and blended with 8% de-activation florisil. The florisil/fat mixture was packed into disposable filtration columns. This column was tandem with an octadecyl SPE column and was eluted with acetonitrile. The pesticide residues were determined by gas chromatography with electron capture and flame photometric detectors. Three kinds (including OC, OP and synthetic pyrethroid) with a total of 71 pesticides (including their metabolites) were tested in this study. With the exception of isoxthion and flucythrinate with high recovery rates (122% ± 13% and 137% ± 31%, respectively), according to the correlation coefficients for the 71 extracted pesticide standard curves (ranging from 0.9915 ± 0.0176 to 0.9999 ± 0.0200, n = 5), average recovery rate (ranging from 68 ± 9% to 117 ± 11%, n = 25 for each insecticide), interassay variability (ranging from 3 ± 3% to 17 ± 12%, n = 25 for each insecticide), intra-assay variability(ranging from 3 to 19%, n = 5 for each insecticide) indicated that the methodology is acceptable for the extraction, determination, and screening of theses residues in beef fat. The detection limits for OCs, OPs and synthetic pyrethroid pesticides are 2~21 ng/g, 6~31 ng/g and 3~118 ng/g, respectively. Comparing with studies conducted by the National Analytical Reference Laboratory in Western Australia in the field of pesticide residue testing in beef fat, the results indicated that the present method could accurately measure commonly used pesticide chemicals.
本研究建立利用串聯式固相萃取(tandem solid phase extraction)技術,自牛油中同時萃取3類主要農藥,包括有機氯(organochlorine)、有機磷(organophosphate)及合成除蟲菊(synthetic pyrethroid) 類農藥,並完成淨化步驟的方法,以利畜產品中農藥殘留檢測的工作。將溶解的牛油(0.5 g)與去活性的矽酸鎂(florisil)粉末混合後填充於管柱中,再與octadecyl (C18)管柱串聯並以乙腈(acetonitrile)為溶劑進行淋洗,洗出液經濃縮後分別以氣相層析儀(gas chromatography)附電子捕獲式檢出器(electron capture detectors)或火燄光度檢出器(flame photometric detector)進行檢測。試驗結果顯示,在3類71種農藥中,各農藥以不同濃度(各5種濃度)標準劑添加於牛油中後,除有機磷藥劑 isoxthion (回收率在122 ± 13%) 及合成除蟲菊藥劑 flucythrinate (回收率在137 ± 11%)外,由回收標準曲線(standard curve)的相關係數(correlation coefficient) (範圍在0.9915 ± 0.0176至0.9999 ± 0.0200之間,n = 5)、各藥劑的平均回收率(68 ± 9%至117 ± 11%之間,n = 25)、每一藥劑在分析內的變異性(inter-assay variability) (範圍在3 ± 3至17 ± 12%)及每一藥劑在分析間的變異性(intra-assay variability) (範圍在3至19%) 得知,本方法至少適用於牛油中3類69種藥劑殘留篩檢的萃取及淨化作業。在設定的儀器條件下,對14種有機氯類藥劑、41種有機磷類藥劑及16種合成除蟲菊藥劑的最低偵測界限(detection limits)分別為2~21 ng/g、6~31 ng/g及33~118 ng/g。在由西澳大利亞National Analytical Reference Laboratory舉辦的盲樣測試中,亦顯示此方法可有效的檢測出牛油中上述3類藥劑的殘留。 |