食用油脂中多種型態維生素E檢驗方法之建立   全文下載

Simultaneous Quantification of Vitamin E Homologues and Its Derivative in Edible Oils

維生素E為具有提高生育能力及抗氧化活性之6-hydroxychromane化合物總稱，自然界之維生素E包含4種生育醇（α-、β-、γ-及δ-生育醇）與4種三烯生育醇（α-、β-、γ及δ-三烯生育醇）。本研究考量實驗室使用分析系統之普及性，研發以逆相液相層析系統搭配螢光檢出器連接串聯式質譜儀，同時分析食用油脂中9種型態維生素E之檢驗方法。將檢體以正己烷溶解，經固相萃取匣淨化、氮氣吹乾再以甲醇回溶後，以Agilent Poroshell 120 PFP管柱，於柱溫40℃，流速0.27 mL／min，移動相為1％甲酸溶液及含1％甲酸之甲醇溶液之梯度流洗層析，並搭配螢光檢出器於激發波長298 nm及放射波長345 nm檢測8種維生素E（dl-α-tocopherol、dl-β-tocopherol、dl-γ-tocopherol、dl-δ-tocopherol、d-α-tocotrienol、d-β-tocotrienol、d-γ-tocotrienol及d-δ-tocotrienol），再以串聯質譜儀分析乙酸α-生育醇酯（dl-α-tocopheryl acetate），可於30分鐘內完成分析。乙酸α-生育醇酯之線性範圍為0.001－0.5μg／mL，α-三烯生育醇之線性範圍為0.01－1μg／mL，其餘7種維生素E之線性範圍均為0.005－1μg／mL，其線性迴歸之決定係數皆大於0.99。以含極微量生育醇之椰子油為基質，進行4種生育醇之添加回收試驗，於10及50μg／g添加試驗中，其平均回收率分別為84.26－91.24％及89.62－94.79％，變異係數分別為0.76－2.41％及1.50－1.88％。另以含極微量三烯生育醇之苦茶油為基質，進行4種三烯生育醇之添加回收試驗，於10及50μg／g添加試驗中，其平均回收率分別為73.70－86.30％及81.78－93.36％，變異係數分別為1.68－8.42％及2.33－4.27％。椰子油及苦茶油中之乙酸α-生育醇酯添加回收試驗，於低濃度（10μg／g）添加試驗中，其平均回收率分別為77.69及70.06％，變異係數為3.10及0.54％；於高濃度（50μg／g）添加試驗中，其平均回收率分別為78.73及71.90％，變異係數分別為0.50及2.53％。整體而言，本研究方法之準確度及精密度皆良好，且定量極限均為10μg／g，應用於10件市售產品中該9項成分含量調查檢驗，其中5件具維生素E標示產品，其檢測值均符合國內相關法規要求。

Vitamin E is a collective term of 6-hydroxychromane compounds which exhibit biological activities of fertility and anti-oxidation. Vitamin E includes 4 tocopherols (α-, β-, γ- and δ-form) and 4 tocotrienols (α-, β- , γ- and δ-form). Considering the popularity of analytical instrument systems, a reverse-phase UPLC system connected with a fluorescence detector and a triple-quad tandem mass spectrometer was developed for this purpose. This method was able to simultaneously analyze 9 forms of vitamin E in edible oils. The method validation results showed that the linear range of the calibration curves for α-tocotrienol was 0.01 - 1 μg/mL, for α-tocopheryl acetate was 0.001 - 0.5 μg/mL, and for other seven forms of vitamin E were 0.005 - 1 μg/mL. The R2 of the calibration curves for 9 analytes were above 0.99. The average recoveries of 4 tocopherols spiked in the coconut oil at the levels of 10 and 50 μg/g were between 84.26 - 91.24% and 89.62 - 94.79%, with coefficients of variance between 0.76 - 2.41% and 1.50 - 1.88%, respectively. The average recoveries of 4 tocotrienols spiked in the camellia oil (with trace level of tocotrientols about 10 μg/g) at 10 and 50 μg/g were between 73.70 - 86.30% and 81.78 - 93.36%, with coefficients of variance were 1.68 - 8.42% and 2.33 - 4.27%, respectively. The recoveries of α-tocopheryl acetate fortified in coconut oil and camellia oil at the level of 10 μg/g were 77.69 and 70.06% with coefficients of variance 3.10 and 0.54%, respectively. The recoveries of α-tocopheryl acetate fortified in coconut oil and camellia oil at the level of 50 μg/g were 78.73 and 71.90% with coefficients of variance 0.50 and 2.53%, respectively. The limits of quantitation were 10 μg/g for 9 forms of vitamin E. A surveillance consisted with 10 commercial edible oils was conducted. The results showed that the tested values of vitamin E in 5 products with labeled vitamin E were in accordance with the regulation.