HPLC与分光光度法测定潲水油中胆固醇的比较

潲水油一直关系食品安全的重要问题,如何有效的检测潲水油将关系到消费者食用油脂的安全性。基于该问题,根据潲水油主要来源于餐桌往往会有动物脂肪混入,在油脂净化过程中会残留少量的胆固醇,从而可以有效的鉴别植物油脂中是否非法添加了潲水油。对紫外分光光度法和高效液相色谱法测定模拟潲水油中的胆固醇,由于植物油中含有的甾醇干扰,紫外分光光度的方法无法准确测定。高效液相色谱将甾醇和胆固醇测底分离,可以准确的测定植物油脂中的胆固醇含量,具体条件为：C₁₈色谱柱,100%甲醇洗脱,在205nm紫外检测。样品处理：油脂中30mL无水乙醇、10mL氢氧化钾于70℃水浴皂化1h,然后用石油醚提取,浓缩,检测。在该条件下回收率达到75%以上,当植物油中胆固醇含量大于0.35g/L可以进行准确定量。采用该法进行盲测可以准确判断出模拟潲水油,对市场上的植物油样采集进行测定,发现有两种油中含有微量的胆固醇。

Cholesterol Determination in Hogwash Oil by High Performance Liquid Chromatography and UV Spectrophotometry

Hogwash oil is always an important factor concerning food safety, and this study aims to establish an effective method to detect hogwash oil. The determination method of cholesterol in hogwash oil is as follows: first, samples are saponificated with anhydrous ethanol and potassium hydroxide in 70℃ water, and extracted with petroleum ether; then, sterol and cholesterol are separated by high performance liquid chromatography (HPLC); at last, clear chromatographic peak are observed under 205 nm. By testing concentrated liquid after filtering, extraction rate of cholesterol exceeds 75%, and the accurate and quantitative detection could be obtained when cholesterol content is over 0.35 g/L. This method is used in blind test, and it could accurately detect the simulation pigwash oil, and traces of cholesterol are found in two kinds of vegetable oil collected from the market.