电感耦合等离子体质谱法测定地球化学样品中铌钽钨锡

采用HCl-HNO3-HF-HClO4溶解地球化学样品,以50 mg/L酒石酸-1％ HCl为测定介质克服了铌、钽、钨、锡易水解的特性,选择93 Nb、181 Ta、182W、118Sn为分析同位素及50 ng/mL185Re为内标,建立了电感耦合等离子体质谱法(ICP-MS)同时测定地球化学样品中微量铌、钽、钨、锡的...

Determination of niobium,tantalum, tungsten and tin in geochemical samples by inductively coupled plasma mass spectrometry

The geochemical samples were dissolved with HCl-HNO₃-HF-HClO₄. 50 mg/L tartaric acid-1% HCl was used as test medium to overcome the easy hydrolysis characteristic of niobium, tantalum, tungsten and tin. ⁹³Nb, ¹⁸¹Ta, ¹⁸²W and ¹¹⁸Sn were selected as the analytical isotopes, and ¹⁸⁵Re of 50 ng/mL was used as the internal standard. A new method for simultaneous determination of trace niobium, tantalum, tungsten and tin in geochemical sample by inductively coupled plasma mass spectrometry (ICP-MS) was established. Under the selected experimental conditions, the mass spectral intensity of niobium, tantalum, tungsten and tin had good linear relationship with the corresponding mass concentration in range of 0.01-100 ng/mL. The correlation coefficients were between 0.999 6 and 0.999 8. The limit of detection was 0.003-0.090 ng/g, and the limit of quantification was 0.010-0.300 ng/g. The experimental method was applied to the determination of niobium, tantalum, tungsten and tin in certified reference materials of rock, soil and stream sediment. The results were basically consistent with the certified values. The relative standard deviations (RSDs, n=9) were 1.8%-4.9%, 2.4%-5.3%, 2.0%-5.3% and 1.7%-4.9%, respectively. The contents of niobium, tantalum, tungsten and tin in actual samples of rock, stream sediment and soil were determined according to the experimental method. The RSDs were 2.1%-4.1%, 2.3%-4.0%, 2.4%-4.2% and 1.6%-4.3%, respectively.