稀土氧化锌中锌及稀土含量的连续测定法

Continuous Determination of Zinc and Rare-earth Amounts in Rare-earth Zinc Oxide

研究了稀土氧化锌中锌及稀土含量的连续测定方法。用抗坏血酸、磺基水杨酸及硫脲在微酸性介质中分别掩蔽铁、铝及铜离子；在ｐＨ＝５．５的六胺缓冲溶液中用ＥＤＴＡ标准滴定溶液滴定至二甲酚授指示剂变色测定锌及稀土总量：继用氟化铵置换出与稀土元素络合的ＥＤＴＡ，用锌标准溶液测得稀土含量。此方法具有原理可靠、操作简便、测定快速、结果准确等特点。

The continuous determination of zinc amd rare-earth amounts in rare-earthzinc oxide was investigated. The iron .aluminium and copper ions were respectively screenedby ascorbic acid,sulfosalicylic acid and thiourea in an acidulous medium ;the total amounts ofzinc and rare-earth were determined by titrating with EDTA titrant in hexamine buffer solution with 5. 5pH till the xylenol orange indicator discolored; then EDTA in the rare-earthcomplex was replaced with ammonia fluoride,and the amount of rare-earth was determinedwith the standard zinc solution. The method featured reliable principle,simple operation,fastdetermination and accurate results.