巯基葡聚糖凝胶分离富集吸光光度法测定微量锗的研究

PHOTOMETRIC DETERMINATION OF GERMANIUM(Ⅳ) WITH o-NPF IN THE PRESENCE OF CTMAB——PRECONCENTRATION OF GERMANIUM(Ⅳ) BY ADSORPTION ON SULFHYDRYL DEXTRAN GEL

研究了在溴化十六烷基三甲基铵存在下锗与邻硝基苯基荧光酮的显色反应。结果表明,在HCl介质中,锗与邻硝基苯基荧光酮形成了灵敏度很高的络合物,其ε=1.86×10~5L·mol^(-1)·cm^(-1),组成比Ge(Ⅳ):邻硝基苯基荧光酮=1:3,采用巯基葡聚糖凝胶(SDG)分离富集,使方法的选择性得到了提高,可用于多种样品中痕量锗的测定,结果满意。

In a HCl medium of 0.48～0.96mol·L^(-1) and in the presence of CTMAB, Ge(Ⅳ) reacts with 2, 6,7-trihydroxy-9-(2'-nitrophenyl)-3-fluorone (o-NPF) forming a colored complex with its absorption maxima at 520nm and an apparent molar absorptivity (ε) of 1.86×10~5L·mol^(-1)·cm^(-1). Mole ratio of the complex is found to be Ge(Ⅳ) : o-NPF=1 : 3. Preconcentration of the Ge(Ⅳ) and simultaneously separated from the co-existing-inter-fering ions by adsorption on a column filled with sulfhydryl dextran gel (SDG) is made before the photometric deterruination. It is found that in an alkaline medium of pH 12～14, adjusted with NaOH solution, the rate of adsorption achieved to a value of 100%. The Ge(Ⅳ) on the SDG is desorbed by 0.01mol·L^(-1) HCl solution and reacted with o-NPF. The proposed method has been applied to the analysis of some drink samples with satisfactory results.