根據流行病理學調查顯示造成人類致癌的因素中飲食占了60%。其中一種被US-EPA列為B2致癌物亞硝胺(N-nitrosamines)是令人關注探討的一群化合物，亞硝胺這一類化學物質具有高毒性、誘發突變及致癌的性質。近30年來，許多研究指出食物中含有亞硝化合物，主要因為亞硝胺容易由亞硝酸鹽或硝酸鹽與二級胺類發生胺化反應而產生，例如本研究的醃製肉品等加工食品。 本研究主要是發展出一套快速、溶劑量少且高通量的樣品前處理方法。使用微波輔助萃取(microwave-assisted extraction，MAE)及搭配分散微固相萃取法(dispersive micro-solid phase extraction，D-µ-SPE)，一次可萃取30組肉類樣品中的亞硝胺。本研究除了開發新的檢測肉品中亞硝胺的技術外，並使用實驗統計設計(statistical experimental design)及變異數分析(analysis of variance，ANOVA)來做最佳化的探討。將肉品中亞硝胺萃取到水溶液裡，其中因子為時間及溫度，最佳化結果為10分鐘、100 C。而在D-µ-SPE方面，選用100 mg 商業化分子篩-Carboxen 1000，搖盪30分鐘完成萃取後，快速過濾吸附劑以200 μL的二氯甲烷回溶。以10 μL大體積進樣方式導入氣相層析儀，可測得亞硝胺方法偵測極限至0.006 ng/g。檢測市面上肉類產品其萃取相對標準偏差小於20%。The presence of N-nitrosamines (NAms) in food stuff has become a significant issue on Public health in last decades, NAms are throught to be mutagenic and carcinogenic with action on the liver, kidney and lung. These compounds are formed by reaction of N-containing substances. In this study, a sensitive procedure, microwave-assisted extraction (MAE) coupled dispersive micro solid-phase extraction (D-μ-SPE), was developed to extract N-nitroso-dimethylamine (NDMA) and other six volatile N-nitrosamines (NAms) from meat products. The parameters affecting the MAE and D-μ-SPE efficiency were systematically investigated. For MAE, 5-g of pasted meat sample was extracted in 30 mL sodium hydroxide (0.025 M) solution at 100 C for 10 min. The best D-μ-SPE conditions were immersing 100 mg of Carboxen 1000 adsorbent in MAE extract, after 30 min of extraction by vigorously shaking, the NAms were then desorbed by 200 μL of dichloromethane. A 10 μL aliquot was determined by gas chromatography with chemical ionization mass spectrometry (GC-CI-MS) using the selected-ion -storage (SIS) mode. The limits of detection (LODs) were 0.006−0.12 ng/g.
