Determination of trace copper and vanadium in titanium dioxide by inductively coupled plasma atomic emission spectrometry with diammonium hydrogen phosphate separation
Abstract：The determination of trace copper and vanadium in titanium dioxide sample by inductively coupled plasma atomic emission spectrometry (ICP-AES) was interfered with the titanium matrix. The titanium matrix was precipitated 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 precipitation 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 fullyreact 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 7 μg/mL, respectively. The proposed method was applied to determination of copper and vanadium in titanium dioxide actual samples. The relative standard deviation (RSD) was not more than 1.2%, and the recoveries were between 90% and 117%. The proposed method was applicable for the routine analysis of titanium dioxide.
