络天青S-溴化十六烷基吡啶吸光光度法测定混合稀土中钪的研究

STUDY OF THE ABSORPTIOPHOTOMETRIC DETERMINATION OF SCANDIUM IN RARE EARTH MIXTURE WITH CAS IN THE PRESENCE OF CPB

研究了钪-络天青S(CAS)-溴化十六烷基吡啶(CPB)三元体系的光度特性,确定了测定混合稀土中钪的最佳条件,探讨了表面活性剂的增敏机理,提出了一种灵敏度高、选择性好的测钪方法。其络合物在λ_(max)=630nm处的ε为1.01×10~5,灵敏度是相应二元体系的四倍。在0～6.5/25ml范围符合比耳定律。最低检出限1.4ng·ml^(-1)。应用于合成稀土样品中钪的测定,结果满意。

The absorptiophotometric properties of the chromogcnic reaction of scandium with CAS in the presence of CPB and the mechanism of the sensitizing effect of the surfactant CPB are studied thoroughly and reported in this paper,Under the op timurn conditions selected,scandium can be determined selectively in a mixture of rare earth metal mixture and the results ob tained are quite satisfactory , Beer ' s law is obeyed over the concentration range of Sc 0-6 . 5 μg / 2 5 rnl with a detectionlimit of 1. 4ng ?ml-1. The calculated apparent molar absorptivity (ε) is 1. 01 × 105 at 630mn,the λmax of the reaction system. The ε value mentioned above is 4 times as large as that of the color reaction is the absence of CPB.