食品中磷测定方法的改进

对食品中磷的测定方法进行改进和完善,研究出新的检测方法。使用微波消解仪,在食品中加入硝酸密闭消解,并用抗坏血酸代替国标方法中的对苯二酚,同钼酸铵、亚硝酸钠溶液与消解液反应,用钼蓝反光光度法在660 nm波长处测定样品中磷的含量。结果表明,该方法可以将样品消解完全,磷的含量与吸光度呈线性关系,相关系数为0.999 8,对样品的加标回收率为95.4%~105.0%,本方法与国标法测定值相吻合。该方法操作简单,用微波消解技术大大缩短了样品前处理的时间,用抗坏血酸代替国标方法中的对苯二酚避免了有毒试剂对化验员的危害及环境的污染,重复性好,适于食品中磷元素含量的测定。

Improvement of determination method for phosphorus in food

In this paper, a new method for the determination of phosphorous in food samples was set up. HNO3 was put in the food sample, which was sealed digested using microwave digestion oven. By replacing Hydroquinone in GB stan-dard method with ascorbic acid, the digested solution was reacted with ammonium molybdate and sodium sulfite. Con-tent of phosphorous was determinate with molybdenum blue spectrophotometry at 660 nm wavelength. Results：The sample digestion could be completely done, phosphorus content and the absorbance were linear correlation, the coeffi-cient was 0.999 8,sample recovery was 95.4%~105.0%, and they were consistent with national standard method. Con-clusion： Microwave digestion technique greatly reduced the sample＇s pre-treat time. Samples which were treated with ascorbic acid instead of hydroquinone in the national standard methods avoided contamination of toxic reagents to labora-tory personnel and environmental hazards. This method was simple, reproducible, and suitable for the determination of phosphorus content in foods.