钒钼黄分光光度法检测液态特殊食品中磷含量的优化

目的建立钒钼黄分光光度法检测低磷含量液态婴幼儿配方食品、液态特殊医学用途配方食品等特殊食品中磷含量的分析方法。方法试样经消解,磷在酸性条件下与钒钼酸铵生成黄色络合物钒钼黄,于440 nm测定试样溶液中钒钼黄的吸光度值,幵与标准系列比较定量。对3种基质液态特殊食品的磷含量进行测定。结果增大称样量能满足方法准确度和精密度要求;称样量为4 g时,回收率范围为92.4%～107.0%,相对标准偏差为0.8%～3.7%;方法定量限为30 mg/100 g。结论该方法能够准确测定液态配方食品中较低含量的磷,适合液态婴幼儿配方食品、液态特殊医学用途配方食品等特殊食品中磷含量的测定。

Optimization of determination of phosphorus content in special liquid food by vanadium molybdenum yellow spectrophotometry

Objective To establish a method for the determination of low phosphorus content in liquid infant formula food and liquid formula food with special medical use by vanadium molybdenum yellow spectrophotometric method. Methods After sample digested, the phosphorus reacted with ammonite vanadate molybdate to form yellow complex vanadium-molybdenum yellow in the medium of acid, and the absorbance value of vanadium-molybdenum yellow in sample solution was determined at 440 nm, and quantitated by a series of phosphorus standard solution. The phosphorus content of 3 kinds of special liquid foods was determined. Results The accuracy and precision of the method were satisfactory by increasing sample quality. When the sample quality was 4 g, the recoveries ranged from 92.4% to 107.0%, and the relative standard deviations were 0.8%?3.7%. The limit of quantitation of the method was 30 mg/100 g. Conclusion This method can accurately determine the low phosphorus content in liquid formula food, which is suitable for the determination of phosphorus content in liquid infant formula food, liquid formula food with special medical use and other special liquid foods.