偶氮胂Ⅲ光度法测定铝合金中微量钪  

Spectrophotometric determination of micro scandium in aluminum alloy with arsenazo-Ⅲ

作　　者：田伦富[1] 邹德霜[1] 代以春[1] 

机构地区：[1]中国工程物理研究院机械制造工艺研究所,四川绵阳621900

出　　处：《冶金分析》2015年第10期60-63,共4页Metallurgical Analysis

基　　金：国防预研基金项目(K81713Y)

摘　　要：在pH 1.8的HCl-KCl缓冲溶液中,钪与偶氮胂Ⅲ形成稳定的紫红色络合物,其最大吸收峰在680nm处。研究了酸度、偶氮胂Ⅲ用量、反应时间、共存元素等因素对显色反应的影响。结果表明：酸度和偶氮胂Ⅲ用量对体系吸光度影响较大,最佳pH值和偶氮胂Ⅲ体积范围分别为1.5~2.0和1.5~2.5mL;温度对显色反应影响不大,室温下显色5min即可测定,且吸光度在120min内基本保持不变;铁、钛、锆严重干扰钪的测定,采用铜铁试剂沉淀分离的方法可消除其影响。在最佳条件下,钪在0~1.0μg/mL范围内符合比尔定律,表观摩尔吸光系数为1.8×104 L·mol-1·cm-1。方法用于铝合金中微量钪的测定,相对标准偏差（RSD）不超过2%,测定结果与标样认定值或对比方法（电感耦合等离子体原子发射光谱法）测定结果基本一致。The scandium could react with arsenazo-Ⅲin HCl-KCl buffer solution at pH 1.8to form stable purple red complex with maximum absorption peak at 680 nm.The effect of acidity,arsenazo-Ⅲ dose,reaction time and coexisting element on the coloring was studied.The results indicated that the acidity and arsenazo-Ⅲ dose had great influence on the system absorbance.The optimal range of pH and arsenazo-Ⅲdose was 1.5-2.0and 1.5-2.5mL,respectively.The temperature exhibited little influence on the coloring reaction.The determination could be conducted after coloring at room temperature for 5min.Moreover,the absorbance could be basically remained within 120 min.The determination of scandium was seriously interfered by iron,titanium and zirconium,which could be eliminated by precipitation separation using cupferron.Beer＇s law was obeyed for scandium in range of 0-1.0μg/mL under the optimal conditions.The apparent molar absorptivity was 1.8×104 L·mol-1·cm-1.The proposed method was applied to the determination of trace scandium in aluminum alloy,and the relative standard deviations（RSD）were not more than 2%.The determination results were basically consistent with the certified values of standard samples or those obtained by comparative method（inductively coupled plasma atomic emission spectrometry）.

关 键 词：钪 偶氮胂Ⅲ 铜铁试剂 分光光度法 铝合金 

分 类 号：TG115.33[金属学及工艺—物理冶金]