金属氧化物中磷含量测定的实验研究

Experimental Study on the Determination of Phosphorus Content in Metal Oxides

建立了钼酸铵(测定磷的重要试剂)分光光度法测定金属氧化物中磷含量的分析方法。使用1-氨基-2-萘酚-4-磺酸、亚硫酸钠和偏重亚硫酸钠混合液作为还原液,浓硝酸溶解样品。在深入分析影响测量磷含量准确度的多种因素基础上,本实验从硝酸用量,溶液酸度控制,最佳显色波长,比色皿的选择,显色持续时间,工作曲线和标准曲线是否重合等多个方面进行实验条件的研究。结果表明工作曲线和标准曲线重合,可选用标准曲线代替工作曲线。最佳实验条件为硝酸加入量2mL,溶液浓度1mol/mL,吸收波长710nm,显色持续时间为30min。该方法的标准曲线y=75.031x+0.1132,线性相关系数r=0.9997,线性范围3.57~57.14μg/mL,回收率95.3%~103.2%。该方法操作简单,实验过程稳定,结果重现性好,可用于金属氧化物样品中磷含量的测定。

A spectrophotometric method for the determination of phosphorus in metal oxides by ammonium molybdate(an important reagent for the determination of phosphorus)was established.A mixture of 1-amino-2-naphthol 4-sulfonic acid,sodium sulfite and sodium metabisulfite was used as reducing solution and concentrated nitric acid was used to dissolve the samples.Many factors affecting the accuracy of phosphorus content mea-surement were analyzed.The optimum experimental conditions were studied from the following aspects:the amount of nitric acid,the control of solution acidity,the time of color development,the optimum wavelength of color development,the duration of color development,the coincidence of working curve and standard curve.The results showed that the working curve coincides with the standard curve,and the standard curve could be used to replace the working curve.The optimal experimental conditions were 2 mL of nitric acid,1mol/mL of solution acidity,710 nm of absorption wavelength and the duration of color development is 30 minutes.The standard curve y=75.031x+0.1132,the linear correlation coefficient r=0.9997,the linear range of 3.57~57.14μg/mL,the recovery of 95.3%~103.2%.The method is simple,stable and reproducible,and can be used for the determination of phosphorus content in metal oxides samples.