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    电感耦合等离子体原子发射光谱法测定钡精矿中钡、钨的含量

    ICP-AES Determination of Barium and Tungsten in Barium Concentrate

    • 摘要: 样品0.100 0 g,与混合熔剂(mNa2CO3mNa2O2为1:2) 2.0 g混匀后于750℃熔融。冷却后,用2.0%(质量分数)碳酸钠溶液50 mL加热溶出熔块。过滤后,滤液(其中含有以钨酸盐存在的钨)加水定容至250 mL。分取25.0 mL加入2.5%(质量分数)酒石酸溶液5 mL,2 min后加入盐酸(1+9)溶液50 mL,加水稀释至100 mL。将过滤后所得不溶物(其中含碳酸钡沉淀)与硝酸15 mL煮沸3 min,加水定容至100 mL,静置,分取上清液10.0 mL,加水稀释至100 mL。采用电感耦合等离子体原子发射光谱法分别测定上述两溶液中钨及钡的含量。用所提出方法测定了国家标准物质(GBW 07284和GBW 07811)中三氧化钨和氧化钡的含量,测定值与认定值相符,其相对标准偏差(n=6)分别为1.6%,0.24%。

       

      Abstract: The sample (0.100 0 g) was mixed with 2.0 g of a mixed flux (mNa2CO3:mNa2O2=1:2) and fused at 750℃. After cooling, the melt was taken up with 50 mL of 2.0% (w) Na2CO3 solution by heating, and the mixture was filtered after cooling. The filtrate (containing the tungsten as tungstate) was made up its volume to 250 mL with water. An aliquot of 25.0 mL was taken, 5 mL of 2.5% (w) tartaric acid solution were added and after 2 min, 50 mL of HCl (1+9) solution were added, and the solution was diluted to 100 mL. The insolubles (containing the barium as BaCO3 precipitate) were boiled with 15 mL of HNO3 for 3 min, and made up its volume to 100 mL with water. After standing, an aliquot of 10.0 mL of the supernatant was taken and diluted to 100 mL with water. The above mentioned 2 solutions were used to determined tungsten and barium separately by ICP-AES. The proposed method was used to determined W and Ba in 2 CRMs (GBW 07284, GBW 07811), giving results of WO3 and BaO in consistency with the certified values, and RSDs (n=6) of 1.6% for WO3 and 0.24% for BaO.

       

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