分光光度法测定稀土氧化物中微量钙至今未见到国外资料,国内虽有个别方法,但因分离流程冗长并不适用。本工作在柠檬酸钾碱性溶液中,用偶氮氧化偶氮BN—磷酸三丁酯—环己烷(以下简称AT溶液)萃取钙,可与大量稀土元素及铁、铝等干扰元素分离,再用0.02 M PMBP—氯仿萃取分离残余的微克量的稀土元素,最后用乙二醛缩双(-邻氨基酚,以下简称GBHA)萃取光度法或双环己酮草酰二腙(简称BCO)-铜间接分光光度法(后一方法不适于含镁量较高的样品)测定。所拟定的方法快速、简便、准确度较 Spectrophotometric determination of trace amounts of rare earth oxides of calcium has not seen foreign information, although the domestic individual method, but the lengthy separation process does not apply. This work is to extract calcium from the azo-oxidative azo BN-TBP-cyclohexane (hereinafter referred to as AT solution) in alkaline solution of potassium citrate, which can be separated from a large amount of rare earth elements and interference elements such as iron and aluminum, And then 0.02 M PMBP-chloroform extraction and separation of residual micrograms of rare earth elements, and finally with glyoxal shrink bis (- o-aminophenol, hereinafter referred to as GBHA) extraction spectrophotometry or dicyclohexanone oxalydihydrazone (BCO) - Copper indirect spectrophotometry (the latter method is not suitable for samples with higher magnesium content) determination. The proposed method is fast, easy and accurate