二溴对氯偶氮甲磺(DBCMSA)光度法测定铈组稀土的研究

Study on Spectrophotometric Determination of Cerium Subgroup Rare Earths with A New Color Reagent Dibromo-p-chloro-methylsufonazo (DBCMSA)

研究了新显色剂二溴对氯偶氮甲磺与铈组稀土离子的显色反应。在盐酸、磷酸、高氯酸、硫酸、硝酸介质中，与铈组稀土形成稳定的络合物，最大吸收在６４４ｎｍ 。在测定钢样中铈组稀土总量时，反应有很高的选择性，不需加任何掩蔽剂，分析结果与标准值基本相符。

Color reactions of cerium subgroup rare earths with DBCMSA are studied in detail. In hydrochloric, phosphoric, perchcoric, sulfuric and nitric acid media, DBCMSA reacts with cerium subgroup rare earths to form stable complex having an absorption maximun at 644nm. The color reaction is found to be highly selective and has been successfully employed to determine the total amounts of the cerium subgroup rare earths in steel samples without adding any masking agents. Results obtained are well in agreement with standard values.