分光光度法测定鸡蛋黄卵磷脂含量

Spectrophotometric Determination of Egg-yolk Lecithin Content

建立鸡蛋黄卵磷脂含量快速测定的分光光度检测方法。将鸡蛋黄用95%的乙醇溶液处理,分离蛋黄脂质。粗提的蛋黄脂肪经高氯酸-硝酸消化液消化后与钒钼酸铵反应,于分光光度计400 nm处进行比色测定磷含量,再乘以系数25即为卵磷脂含量。在0.5 g空白样品中分别添加50μg、100μg和200μg3个不同量的磷标准溶液,测定回收率。磷标准曲线在0～25μg/ml浓度内呈线性相关,相关系数(r)为0.994。回收率为84.3%～93.4%,精密度为1.93%～2.90%。该方法符合食品卫生分析要求,可用于鸡蛋黄卵磷脂含量分析。

The purpose of this study was to set up a rapid determination method of yolk lecithin content with spectrophotometer.The egg-yolk lipid extracted with 95% ethanol was digested by perchloric acid and nitric acid and then reacted with ammonium vanadate-molybdate.The lecithin content equals to 25 times of the phosphorus content determined with spectrophotometer at 400 nm.The recoveries of phosphorus were determined by adding 50 μg,100 μg and 200 μg phosphorus to 0.5 g blank samples.The calibration curve was linear in a concentration range of 0-25 μg/ml phosphorus with correlation coefficient of 0.994.Recoveries of phosphorus at the 3 fortified levels ranged from 84.3% to 93.4%,and the precision ranged from 1.93% to 2.90%.