簡易甲酯化處理－－氣相層析法分析食用油脂中之合成抗氧化劑   全文下載

Gas Chromatographic Determination of Synthetic Antioxidants in Edible Fats and Oils-A Simple Methylation Method

本研究建立了食用油脂中合成抗氧化劑BHA、BHT及TBHQ之簡便氣相層析分析定量法。將2-3 滴（60-80 mg）之油脂樣品以10%之tetramethylammonium hydroxide（TMAH）甲醇溶液1 mL甲酯化後，再以4-6 mL乙醚萃取其中之抗氧化劑，加入0.2%（w／v）之tetradecanol（14C-OH）內標準品溶液50 μL，即可直接注入氣相層析儀分析之。添加回收實驗中，BHA、BHT及TBHQ之回收率為94-106%，變異係數均小於9%。以本方法測定18 件市售動、植物油脂，包括橄欖油、葵花油、花生油、大豆沙拉油、蔬菜油及動植物混合油等之BHA、BHT及TBHQ含量，分別為： 0-50 、0-267 、及0-37 μg／g ， 18 件樣品中檢出含抗氧化劑者達14 件，其中3 件動植物混合油之總抗氧化劑含量達259 ～294 μg／g ，超過CNS之標準添加量200 μg／g 之規定。

A simple method was developed for determining the antioxidants, BHA, BHT and TBHQ in commercial edible fats and oils. In 2-3 drops (about 60-80 mg) of an oil sample, 10% tetramethylammonium hydroxide (TMAH) methanol solution 1 mL was added and vortexmixed for 10-minute methylation. The mixture was then extracted with 4-6 mL ether, 0.2% tetradecanol (14C-OH) 50 μL was added and thoroughly mixed. An aliquot of 0.3 μL of the ether layer was then injected to GC for BHA, BHT and TBHQ analyses. The recoveries from commercial oils were in a range of 94-106%, with a coefficient of variation < 9%. Eighteen commercial edible fat and oil samples of olive, sunflower, peanut, soybean, vegetable and blend oils were analyzed using the developed method. The contents of BHA, BHT and TBHQ were found to be 0-50, 0-267 and 0-37 μg/g. Fourteen out of 18 samples were detected to contain antioxidants. The total antioxidant contents in the three blend oils ranged 259-294 μg/g, which exceeded the Chinese National Standards (CNS) control level of 200 μg/g for edible oils. 本研究建立了食用油脂中合成抗氧化劑BHA、BHT及TBHQ之簡便氣相層析分析定量法。將2-3 滴（60-80 mg）之油脂樣品以10%之tetramethylammonium hydroxide（TMAH）甲醇溶液1 mL甲酯化後，再以4-6 mL乙醚萃取其中之抗氧化劑，加入0.2%（w／v）之tetradecanol（14C-OH）內標準品溶液50 μL，即可直接注入氣相層析儀分析之。添加回收實驗中，BHA、BHT及TBHQ之回收率為94-106%，變異係數均小於9%。以本方法測定18 件市售動、植物油脂，包括橄欖油、葵花油、花生油、大豆沙拉油、蔬菜油及動植物混合油等之BHA、BHT及TBHQ含量，分別為： 0-50 、0-267 、及0-37 μg／g ， 18 件樣品中檢出含抗氧化劑者達14 件，其中3 件動植物混合油之總抗氧化劑含量達259 ～294 μg／g ，超過CNS之標準添加量200 μg／g 之規定。