分光光度法测定金合金中的钆、钇

建立了测定金合金中Gd、Y质量分数的偶氮氯膦Ⅲ分光光度法,研究了基体金的还原条件和提高测定方法选择性的条件。结果表明:亚硫酸可完全还原金,并对Gd(Ⅲ)、Y(Ⅲ)无吸附影响;加入EDTA可提高方法的选择性,一定量常见金属离子不干扰测定;在0.1 mol/L盐酸介质中,体系的最大吸收峰为λmax=673 nm、λmax=672 nm,表观摩尔吸光系数ε6G7d3=6.37×104L.mol-1.cm-1、6Yε72=7.01×104L.mol-1.cm-1,Gd(Ⅲ)、Y(Ⅲ)的质量浓度分别在0~50μg/50 mL、0~40μg/50 mL符合比尔定律,加标准回收率分别为99.80%~100.40%、99.80%~100.30%,测定质量分数为0.6%的Gd、Y,相对标准偏差为0.004%、0.005%。方法选择性好、操作简便、易于掌握,应用于金合金中Gd、Y质量分数的测定,结果满意。

Spectrometrical Determination of Gadolinium and Yttrium in Gold Alloys

A spectrophotometry for the determination of gadolinium and yttrium content in gold alloys using chlorophosphonazo Ⅲ as a chromogenic agent was proposed. The conditions of reductive gold and improving selectivity of the method were established. Results indicated that the gold could be reduced with sulfurous acid and had no effect on adsorption of gadolinium and yttrium. The selectivity of the method can be remarkably improved by addition of EDTA and a certain amount of metal ions had no interference. The maximum adsorption wavelengths of the system are λ_(max)=673 nm and λ_(max)=672 nm, and the apparent molar adsorptivity is ε_(673)~(Gd)=6.37×10~4 L·mol~(-1)·cm~(-1),ε_(672)~Y=7.01×10~4 L·mol~(-1)·cm~(-1). The linear range, recovery of standard addition and relative standard deviation for gadolinium and yttrium are 0～50 μg/50 mL,0～40 μg/50 mL, 99.80%～100.40%, 99.80%～100.30% and 0.004%, 0.005% for determination of 0.6% content, respectively. The proposed method has good selectivity with convenient operation, and it has applied to determination of gadolinium and yttrium content with satisfactory results.