@article{oai:kanazawa-u.repo.nii.ac.jp:00031259, author = {松本, 健 and 小浦, 利弘}, issue = {12}, journal = {分析化学 = Japan analyst}, month = {Dec}, note = {難溶性の硫酸バリウムの分解方法として, 融解剤に硫酸水素アンモニウムを用いる, 迅速簡便な方法を確立した.硬質ガラス製試験管に硫酸塩試料の約10mgと硫酸水素アンモニウムの約2gを入れて混合した後, ガスバーナーの小さなフレームで試験管の底部を550〜600℃に加熱する.分解が進むに従って融解物は無色透明になり, 約5分間の加熱で十分である.冷却後, 固化した融解物を0.05M EDTA-アンモニア水溶液(アンモニア濃度; 3.5M)に加熱溶解し, 溶液中のバリウムを誘導結合プラズマ発光分析法あるいはフレーム光度法で定量する.本法を難溶性のバリウム鉱石の分解に応用し, 試料中のバリウムを定量したところ, 試料を炭酸塩融解して得た値とよく一致した. A simple and rapid method for the decomposition of refractory barium sulfate has been proposed. Barium samples(BaSO_4, ore) were decomposed by fusion with ammonium hydrogen sulfate, which was found to be a suitable powerful flux for dissolving various refractory sulfates. An accurately weighed sample(ca. 10mg) was placed in a dry Pyrex test tube(18mm o.d., 200mm length). Ammonium hydrogen sulfate(ca. 2g) was added to the tube and mixed with the sample by agitating the tube. The bottom of the test tube was gently heated along with a swirling motion over a small gas flame of a Bunsen burner with a fish-tail at a temperature of ca. 550〜600℃. Heating was continued until the melt changed into a colorless, clean and translucent form. Barium sulfate was dissolved by heating for about 5 min. After cooling, the solidified melt was dissolved in 30 ml of a 0.05 M EDTA-ammoniacal solution(3.5 M in ammonia). Finally, the concentration of the barium in the resulting solution was determined by ICP-AES or flame photometry. The proposed method was successfully applied to various sulfates and ores. The barium and other metals in the samples were determined and the analytical results of barium were in good agreement with the values of obtained by fusion with alkali metal carbonate., 金沢大学イノベーション創成センター}, pages = {807--811}, title = {アンモニウム塩融解による難溶性硫酸バリウムの迅速分解・分析(<特集>高度技術を支える分析化学)}, volume = {50}, year = {2001} }