摘要
研究了在 pH11.5～12.5的NH3 -NH4Cl介质和TritonX -100存在下 ,镉试剂2B与铊 (Ⅲ )的显色反应。铊 (Ⅲ )与镉试剂2B形成摩尔比为1∶4的红色配合物 ,在测定波长500nm处 ,表观摩尔吸光系数为9.3×104 L·mol-1·cm-1 。室温下显色反应瞬间完成 ,配合物至少稳定12h ,线性范围是0～800μg/L。建立了采用聚胺酯泡沫塑料吸附铊 (Ⅲ ) ,与其他干扰元素分离 ,在水相体系快速、准确测定地质样品中痕量铊的方法。该法回收率为97.0 %～106 % ,5次测定的相对标准偏差不大于4.1 % 。
It was investigated that the color reaction of thallium with Cadion 2B in the NH3-NH4Cl medium at pH 11.5～12.5 with Triton X-100. Thallium(Ⅲ) and Cadion 2B form a 1∶4(molar ratio)red complex with apparent molar absorptivity 9.3×104 L·mol-1·cm-1 at 500 nm of detection wavelength. The coloration of the reaction is completed for an instant at room temperature and the color is stable at least for 12 h. Beer's law is obeyed in the mass concentration range of 0～800 μg/L for thallium. A method for the determination of trace amount of thallium by spectrophotometry was established using polyurethane foam as an adsorption _ separating material. The proposed method is rapid and accurate and has been applied to determine trace amounts of thallium in geological samples in aqueous solution with recoveries of 97.0%～106%. The relative standard deviations(n=5) are less than 4.1%. The results obtained are in good agreement with the values obtained by AAS.
出处
《分析测试学报》
CAS
CSCD
2000年第3期11-14,共4页
Journal of Instrumental Analysis
基金
广东省自然科学基金资助项目 !(980383)
广东省环保局基金资助项目
