【摘要】 目的建立水和食品中总磷的测定方法。方法将水或食品中的磷元素完全转化为磷酸盐形式,在一定条件下,磷酸盐与钼酸铵形成络合物,再用维生素C(Vc)将该络合物还原剂成钼蓝,钼蓝的吸光度和其浓度在一定范围内呈线性关系,以此测定样品中总磷的含量。结果该方法的线性范围为0.06～4 mg/L,相关系数为0.999 7,检出限为0.06 mg/L,RSD为1.0%,水样、食品样中回收率分别为97.00%～101.88%和95.00%～103.33%。结论该法操作简单,所使用的还原剂对环境无污染,对操作者无健康危害,成本低廉,灵敏度高,可应用于水和食品样品中总磷的测定。更多还原

【Abstract】 Objective To establish a method for the determination of total phosphorus in water and food samples.Methods Firstly,various phosphorus compounds in water or in food samples were converted into phosphates by digestion,under specific reaction conditions,complex ammonium phosphor-molybdate could be formed,this complex could be deoxidized by vitamin C into blue-colored compound,and the absorbency of the compound was proportional to its concentration,by taking advantage of the mechanism,phosphorus in samples could be determined efficiently.Results The linear range of method was 0.06-4 mg/L,the correlation coefficient was 0.999 7,the limit of detection was 0.06 mg/L,and RSDs were 1.0% when samples were determined for 11 times,which contained 30 μg of phosphate.Recoveries of the method were 97.00%-101.88% for water samples and 95.00%-103.33% for food samples respectively.Conclusion The method is simple,sensitive and applicable to the determination of total phosphorus in water and food samples.更多还原