普钙、磷矿中磷的螯溶-差示光度法测定的研究

本文介绍了螯溶-差示光度分析技术用于分析高含量磷的普钙、磷矿样品.提出螯溶反应的机理及其示意式,由测定条件试验得到了螯溶剂在螯溶条件下的极限浓度及其pH值.控制溶解液中柠檬酸溶液浓度,即可防止柠檬酸对钼黄显色的抑制影响,氟离子对钼黄显色的干扰由铝离子络合以消除.用酸溶螯溶-钼酸喹啉重量法作对比试验以及磷的回收试验,验证了螯溶-差示光度法的精密度和准确度.所获结果表明,与酸溶-钼酸喹啉重量法结果比较,含磷高的磷矿,本法的相对误差小于±1%;含磷较低的普钙,其相对误差约为±1.5%.磷的回收率均在99.0-100.4%之间.本法干扰少、无污染,节省设备、试剂,溶样手续简便快速,分析结果准确可靠.

STUDIES ON THE CHELATE DISSOLUTION-DIFFERENTIAL PHOTOMETRIC METHOD FOR DETERMINATION OF PHOSPHOROUS IN CALCIUM SUPERPHOSPHATE AND ROCK PHOSPHATE

This paper deals with the chelate dissolution-differential photometric method for determination of phosporus in calcium superphosphate and rock phosphate samples. A mixed chelate solvent consisting of 15% of citric acid -9% of aluminium nitrate which can control the interference of citric acid and fluorine ion is proposed. The pH value of this mixture solution system is 1.33±0.02. The results obtained has showed that relative error of the chelate dissolution}ifferential photometric methods, as compared with acid dissolution-gravimetric method, is lower by ±1% But for calcium superphosphate with lower phosphorus content, a relative error about ±1.5% is obtained. It is found that the recovery of P₂O₅ added is about 99.0-100.4%.