高效液相色谱测定食品中苯甲酸、山梨酸含量

目的　测定食品中山梨酸、苯甲酸的含量。方法　样品用乙醚—石油醚萃取 ,在 6 0℃水浴上蒸馏除去乙醚—石油醚 ,再在酸性介质中酯化 ,用高效液相色谱分离与测定。结果　标准回收率 :苯甲酸 (10 0 .0 2± 3.2 8) % ,山梨酸 (96 .3± 4 .85) %。最小检出限分别为 :苯甲酸 0 .0 2 2 μg ,山梨酸 0 .0 13μg ,线性关系与回收率较好 ,(r >0 .98)。结论　HPLC法测定食品中苯甲酸与山梨醇防腐剂具有简便、快速、准确的优点 ,值得推广应用

HPLC Analysis of Benzoic and Sorbic Acids Contents

Objective To establish a detective method of contents of benzoicand sorbic acids in fruit beverages.Method High performance liquid chromatography (HPLC) was applied to determine the contents of benzoic and sorbic acids in red apple drink,almond tea,flesh orange and litchi juices.These compounds were extracted from these beverages with ether:petroleum benzine(1∶3) and separated from the solvent plase by distilling on 60℃ water,after the extractives were esterified in acidic medium.These finely benzoic and sorbic acids were then determined by HPLC technique,we used butyl phenylformate as an internal standard,chromatographic conditions included LC-ODS C18 column(0.15m×0.46mm),mobile plase;methanol:potassium dihydrogen phosphate(1∶1,pH＝5.7)，flow rate:0.8ml/min，detection wevelength:at 254nm.sample size:15μl.working temperature:25℃.Results The average recoveries of benzoic and sorbic acids were (100.02±3.28)% and (96.30±4.85)%,respectively.The minimal limits of assay were 0.022μg and 0.013μg,for benzoic and sorbic acids,respectively.The linear correlation coefficients(r) were 0.99 for benzoic acid and 0.98 for sorbic acid,respectively.Conclusions We establised the HPLC method has merits of simple,rapid,accuracy in determination of the benzoic and sorbic acids in fruit beverages.So that,it is suitable for popularized application.