纸上色层分离-硫酸铁铵滴定法测定钛铝铌合金中钛的含量  

Determination of Titanium in Titanium-aluminum-niobium Alloys by Separation of Paper Chromatography-Ammonium Ferric Sulfate Titration Method

作　　者：李甜 田新 胡梦桥 陈雄飞 陈映纯 王雪菲 张力久 LI Tian;TIAN XinHU Meng-qiao;CHEN Xiong-fei;CHEN Ying-chun;WANG Xue-fei;ZHANG Li-jiu(Guobiao(Beijing)Testing&Certification Go.,Ltd.,Beijing 100088,China)

机构地区：[1]国标(北京)检验认证有限公司,北京100088

出　　处：《化学试剂》2021年第5期676-679,共4页Chemical Reagents

摘　　要：滴定钛铝铌合金中钛元素时,由于铌易水解形成沉淀,往往干扰滴定终点的判断和结果的准确度。实验采用纸上色层分离-硫酸铁铵滴定法测定钛铝铌合金中钛的含量。以硝酸-氢氟酸溶解试样,采用纸上色层分离技术将铌与钛分离,在酸性条件下,用铝片将Ti^(4+)还原为Ti^(3+),用饱和碳酸氢钠溶液作为保护溶液,防止Ti^(3+)被氧化。以硫氰酸钾作为指示剂,用硫酸铁铵标准溶液滴定至砖红色为终点。按照上述实验方法测定两个实际样品中钛含量,结果的相对标准偏差RSD分别为0.27%和0.23%(n=11),加标回收率为98.5%~102.4%。方法有良好的精密度和准确度,可用于钛铝铌合金中钛含量的分析。Niobium is easy to hydrolyze to form precipitation when titrating titanium in titanium-aluminum-niobium alloy, which often interferes with the judgment of titration end point and the accuracy of results.The content of titanium in titanium-aluminum-niobium alloy was determined by ammonium ferric sulfate titration.The sample was dissolved with nitric acid and hydrofluoric acid and the niobium and titanium were separated by using a paper color separation technique.Under acidic conditions, Ti^(4+)is reduced to Ti^(3+) by aluminum flakes, a saturated sodium bicarbonate solution was used as a protective solution to prevent Ti^(3+) oxidation.The potassium thiocyanate is used as an indicator and the standard solution of ammonium ferric sulfate is titrated to red as the end point.The titanium content in the two samples was determined via the experimental method.The relative standard deviations(RSD,n=11) of the results were 0.27% and 0.23% with the spiked recoveries were in the range of 98.5%~102.4%.The method can be used for the analysis of titanium content in titanium-aluminum-niobium alloy.

关 键 词：色层分离 硫酸铁铵滴定法 钛铝铌 钛 检测 

分 类 号：O655.23[理学—分析化学]