磷酸氢二铵分离-电感耦合等离子体原子发射光谱法测定钛白粉中痕量铜和钒

摘要

The determination of trace copper and vanadium in titanium dioxide sample by inductively coupled plas-ma atomic emission spectrometry ( ICP-AES) was interfered with the titanium matrix. The titanium matrix was pre-cipitated and separated by diammonium hydrogen phosphate [(NH4)2HPO4]. Then, the content of trace copper and vanadium in titanium dioxide sample was determined by ICP-AES. The sample dissolution method, the precipi-tation conditions of titanium with (NH4)2HPO4 and the determination conditions of ICP-AES were investigated. The results showed that the titanium in 0. 1 g of titanium dioxide sample could be fully react with (NH4)2HPO4 to form Ti(HPO4)2 precipitate in ammonium sulfate and sulfuric acid medium after heating in boiling bath for 3-5 min. The determination results were stable under the selected instrumental conditions with Cu 327. 4 nm and V 292. 4 nm as analytical spectral line. The detection limit of copper and vanadium was 0. 001 μg/mL and 0. 000 7μg/mL, respectively. The proposed method was applied to determination of copper and vanadium in titanium diox-ide actual samples. The relative standard deviation (RSD) was not more than 1. 2%, and the recoveries were be-tween 90% and 117%. The proposed method was applicable for the routine analysis of titanium dioxide.%针对钛白粉样品中钛基体对电感耦合等离子体原子发射光谱法( ICP-AES)测定痕量铜和钒有干扰,提出了利用磷酸氢二铵[(NH4)2HPO4]沉淀分离钛基体后ICP-AES测定钛白粉产品中痕量铜和钒的方法。对溶样方式、(NH4)2HPO4沉淀钛的条件和ICP-AES的测定条件进行研究,结果表明：对于0.1 g钛白粉样品,在H2 SO4和( NH4)2 SO4介质中,用沸水浴加热3~5 min,可使钛与(NH4)2HPO4形成的Ti(HPO4)2沉淀完全,在实验确定的仪器工作条件下以Cu 324.7 mm和V 292.4 nm进行测定,结果稳定。铜和钒的检出限分别为0.001μg/mL 和0.0007μg/mL。应用实验方法对钛白粉实际样品中铜和钒进行测定,相对标准偏差(RSD,n=6)不大于1.2%,加标回收率在90%~117%之间。方法可以用于钛白粉的日常分析。