食品中農藥環氧乙烷之檢驗方法建立   全文下載

Development of a GC-MS/MS Method for the Determination of Ethylene Oxide Residues in Foods

環氧乙烷（ethylene oxide, EtO）為生產聚合物質或介面活性劑時之中間產物，且容易與環境及基質中的氯反應，產生2-氯乙醇（2-chloroethanol, 2-CE）。EtO主要應用在醫療設備滅菌，在美國及加拿大亦可作為燻蒸劑，施用於辛香料、香草植物、乾燥蔬菜及芝麻等作物，惟我國、歐盟、日本及澳洲目前皆未核准作為燻蒸劑使用。109年歐盟食品與飼料快報系統（Rapid Alert System for Food and Feed, RASFF）及國際新聞報導，於多種食品陸續驗出EtO，其殘留風險為國際關注之議題，本研究參考歐盟參考實驗室-單一殘留方法（EURL-SRM）之前處理流程（QuEChERS及QuOil）搭配氣相層析串聯質譜儀（GC-MS/MS），針對EtO及2-CE進行方法開發。經評估後，芝麻、植物膠、食用空膠囊及香辛料為採用QuOil前處理流程，取檢體2 g，以90%乙腈溶液振盪萃取，植物性膠囊則以乙腈溶液振盪萃取，芝麻檢體之萃取時間為30分鐘，植物膠及食用膠囊檢體為2分鐘，辛香料檢體為10分鐘，後經淨化後以氣相層析串聯質譜儀進行分析。冰淇淋基質則採用QuEChERS前處理流程，以乙腈溶液振盪萃取1分鐘後，經淨化後進行分析。因EtO之定性離子對訊號較弱，受基質干擾嚴重，考量歐盟監測結果，陽性檢體均檢出高量2-CE而未檢出EtO，並以轉換係數（0.55）推算EtO之含量，故本研究開發之方法以2-CE為檢測標的，再推算EtO之含量。考量2-CE具微量環境背景值，本檢驗方法之定量極限設定為0.1 mg/kg（相當於環氧乙烷0.055 mg/kg）。確效結果顯示，各類基質於添加0.1 mg/kg及0.2 mg/kg之2-CE，其回收率、重複性及中間精密度皆符合衛生福利部食品藥物管理署（下稱食藥署）公布之食品化學檢驗方法之確效規範。

Ethylene oxide (EtO) is a chemical intermediate in the manufacture of polymer substances or surfactants. It is mainly used for the sterilization of medical equipment, also in the United States and Canada, EtO has long been used as a food fumigant for dry food products, such as herbs, spices, nuts and oily seeds, while this usage is not allowed in Taiwan, EU, Japan and Australia. As EtO is applied to agricultural products, it will rapidly react with chloride or chloride ions from the environment to yield 2-chloroethanol (2-CE). Many countries do not have explicit MRLs for EtO, e.g. Taiwan, Japan, EU and Australia. Since late 2020, “EtO crisis” has been reported in the news or published in the RASFF portal, and there were various foods detected with the unauthorized substance, ethylene oxide (EtO), such as sesame, gum, chili powder and instant noodles. This residual risk is a concern to public health. This study refers to the analytical methods of the European Union Reference Laboratory (EURL) to evaluate EtO and 2-CE in the matrices of oilseeds, gum, spices, ice cream, gelatin and HPMC empty capsules. Ice cream was extracted by a QuEChERS method, other matrices were extracted by QuOil. For HPMC empty capsules, we used acetonitrile as the extraction solvent. In other matrices, we used 90% acetonitrile as the extraction solvent, and then added extraction aids to extract 2-CE by a mechanical shaker for 30 minutes in the case of intact oily seeds, 10 minutes in the case of spices, and 2 minutes in the case of gum and empty capsules. The extracts were centrifuged for 3 minutes at 5000 ×g, 15oC, then the supernatants subjected to a dispersive SPE to clean up, and analyzed 2-CE by a GC-MS/MS (gas chromatography/ tandem mass spectrometer). The results showed that the qualitative ion of EtO is too weak. In real samples, EtO quickly disappears in food through evaporation or reactions, so the exposure of consumers to EtO-related residues through food consumption will be mainly 2-CE. Therefore, this method is to determine the amount of 2-CE expressed as EtO. Considering that 2-CE has a trace environmental background value, the limit of quantification (LOQ) of 2-CE in this study was 0.1 mg/kg (0.055 mg/kg as EtO). All the validation results at the levels of 0.1 and 0.2 mg/kg of 2-CE spiked into various matrices met the requirements of the Validation Guideline of the Food Chemical Testing Method published by the TFDA.