以氣相層析／質譜法建立蔬果中多重殘留農藥檢驗方法之探討   全文下載

Studies on Multiresidue Determination of Pesticides in Fruits and Vegetables by Gas Chromatography/Mass Spectrometry

本研究探討以稍加修飾過之Luke萃取法，自小番茄、青江白菜、包心白菜、敏豆及柑橘五種蔬果中，萃取chlorpyrifos、diazinon、endosulfan、fenarimol、fenvalerate、folpet、iprodione、malathion、methamidophos、phosmet及procymidone，再以gas chromatography／mass spectrometry （GC／MS）進行檢測的多重殘留農藥檢驗方法。十一種農藥在2-50 ng／μL濃度範圍內之標準曲線均呈線性，其迴歸係數（r）介於diazinon的0.97與procymidone的0.99之間。0.5 ppm添加量之回收試驗結果，除methamidophos受到樣品基質干擾外，其餘十種農藥在五種蔬果中的回收率在64.6-124.6%之間。變異係數介於0.3-17.6%，平均為5.3%。最低檢測極限，除methamidophos外，其餘十種農藥在各類受試作物中估計均可低至0.1 ppm。由於質譜儀比一般傳統的GC檢測器具有較高的分子專一性（molecular specificity），且可同時設定追蹤數百種標的離子（target ions），因此GC／MS方法實為一值得政府機關大力開發，用以監測日常食品中殘留農藥的檢驗方法。

A multiresidue method using gas chromatography/mass spectrometry (GC/MS) was evaluated for the determination of several pesticides in fruits and vegetables. The pesticides were extracted using a slightly modified Luke multiresidue procedure, separated by capillary column gas chromatography and detected by mass chromatography with quadrupole mass spectrometer in the electron impact mode. Recovery studies of chlorpyrifos, diazinon, endosulfan, fenarimol, fenvalerate, folpet, iprodione, malathion, methamidophos, phosmet and procymidone were performed at the 0.5 ppm spike level in cherry tomatoes, chin-chian pe-tsai, Chinese cabbages, kidney beans and oranges. Recoveries were between 64.6 and 124.6%, with the exception of methamidophos which produced interference due to the constituents of the samples. Coefficients of variation ranged between 0.3 and 17.6%, with an average of 5.3%. The estimated limits of detection of the pesticides (except methamidophos) in the crops were at the 0.1 ppm level. Because the mass spectrometer is capable of achieving higher levels of molecular specificity as compared to the traditional GC detectors and can be programmed to search for several hundred target ions simultaneously, GC/MS may be a promising method for the use of regulatory agencies with which to monitor pesticide residues in daily food products.