微囊型脂肪粉油脂的常规甲酯化方法优化OA北大核心CSTPCD

The purpose of this experiment is to optimize the methyl-esterification method of microencapsulated fat powder oil.The oil extracted from the samples using acid hydrolysis and petroleum ether.Take 50 mg of the oil and place it in a pressure-resistant vial,then add 2 mL 0.2 mol/L sodium hydroxide-methanol solution and sonicate in a water bath at 65℃.After the saponification was complete,as indicated by phenolphthalein,neutralized with 1 mol/L sulfuric acid-methanol solution until the phenolphthalein is colorless.Then add another 300 μL of sulfuric acid-methanol solution and sonicate again in a water bath at 70 ℃ for 5 minutes.Add a saturated sodium chloride into aqueous solution to assist with phase separation,and extract with isooctane after a desiccating with anhydrous sodium sulfate.Determine the content using Gas Chromatography-Flame Ionization Detector(GC-FID),and evaluate the precision,accuracy,detection limit,and quantitation limit of the method.The results showed that the optimized method of fatty acids in soybean oil standard substance GBW(E)100120 determined by the optimized method were consistent with the standard values,and the precision RSD was 1.25％.The comparison results between laboratories showed that the methyl-esterification rate of this method was more than 95％,the repeatability error limit RSD was 2.71％,and the reproducibility error limit RSD was 4.86％.The limit of detection and limit of quantitation of trans-oleic acid/trans-linoleic acid were 0.004％and 0.011％,respectively.The study indicates that the methods used in the experiment are efficient,accurate,and environmentally friendly,which can provide references for the development of the oil industry and the revision of future standards.