Dissolution procedure for the determination of major and minor elements in La-Sr-Ga-Nb oxide by inductively coupled plasma-optical emission spectrometry

This paper describes a dissolution method for La-Sr-Ga-Nb (LSGN) oxide samples, which are hardly decomposed by conventional acid treatments. The LSGN oxides are not dissolved in any acid solution and do not undergo fusion with alkaline reagents, such as Na₂CO₃. However, the sample can undergo fusion with Na₂B₄O₇ powder. A sample (50 mg) was fused with 1 g of Na₂B₄O₇ in a Pt crucible, whose inside wall was covered with pre-melted Na₂B ₄O₇ (1 g). The melted product was cooled and then dissolved with a mixture of 30 ml HNO₃ (1:1), 2.5 ml H ₂O₂, and 1 g tartaric acid. After the addition of 1.5 ml of H₂O₂ and 5 ml of an Y solution (5 mg/ml) as an internal standard, the solution was diluted to 100 ml and measured by inductively coupled plasma-optical emission spectrometry. Two samples having different chemical compositions were analyzed to yield each in good agreement with the analytical values between two individual measurements.