群馬大学図書館 OPAC

概要: application/pdf<br />Journal Article<br />本研究は,海水の主要無機成分の分離分析において,1本の陽イオン交換樹脂カラムと弱酸溶離液によって試料水中の主要無機陰イオン(SO_4^<2->及びCl^-) … 及び陽イオン(Na^+,K^+,Mg^<2+>及びCa^<2+>)を同時計測するイオン排除/陽イオン交換型イオンクロマトグラフィー(IEC/CEC)の有用性について調べた.通常,IEC/CECは,雨水や河川水のような淡水の分析に利用されているが,高濃度の塩化ナトリウムを含む海水試料への適用は陰イオンの分離能が低いために困難であった.今回は,分離カラムに用いるイオン交換樹脂の担体の種類と交換容量の大きさを変化させ,陰イオンの分離能を改善し,海水試料の分析に応用した.結果として,5.5mM酒石酸と3mM 18-クラウン-6の混合溶液を溶離液としたときの分離カラムの最適条件は,親水性のポリメタクリレートを担体とした交換容量0.15meq./mLの弱酸性陽イオン交換樹脂であった.これより,樹脂相への浸透作用の増大によるSO_4^<2->とCl^-の分離能改善と同時に,良好な陽イオンのイオン交換分離が得られ,20分以内で海水試料中の主要無機成分の分離定量を行うことができた.また,500倍希釈の海水試料を10回連続測定したときのピーク面積の相対標準偏差は,0.2〜2.5%となり良好な結果が得られた. \n\nIon-exclusion/cation-exchange chromatography (IEC/CEC), which consists of a cationexchange resin column and a weak acidic eluent, was used for the simultaneous analysis of common inorganic species (SO_4^<2->, Cl^-, Na^+, K^+, Mg^2+ and Ca^2+) in seawater. When conventional IEC/CEC is applied to seawater containing high concentrations of Na^+ or Cl^-, a poor resolution between SO_4^<2-> and Cl^- was obtained. Therefore, the cation-exchange resin packed to the separation column was reconsidered in terms of the kind of carrier and the magnitude of the exchange-capacity. In this study, the optimal column was a polymethacrylate-based weakly acidic cation-exchange resin with 0.15meq./mL-capacity. This could provide good resolutions of anions by an increase of the penetration effect to the resin phase as well as those cations by the cation-exchange effect. The simultaneous separation and determination was achieved in 20min. The relative standard deviations of the peak areas in consecutive runs (n=10) ranged from 0.2% to 2.5%. 続きを見る

概要: application/pdf<br />Journal Article<br />An acid resistant fluoroapatite coated titanium dioxide (FAp-TiO_2) was synthe … sized by adding a fluoride ion (F^-) to hydroxyapatite (HAp), in order to avoid dissolution of the HAp at an acidic atmosphere. In this study, the optimization of synthetic conditions of FAp-TiO_2 was investigated in terms of the amount of the fluorine (F^-) added to the simulated body fluid, the reaction temperature and the time. The addition of F^- to simulated body fluid was performed after coating HAp on the surface of TiO_2 surface. The crystallinity of FAp phase generated on the TiO_2 was strongly affected by changing the reaction conditions. The optimized synthetic conditions of FAp-TiO_2 as photocatalyst were the addition of 0.25mM-0.5mM F^- in the fluid and then the reaction time for 3h at 60℃. The adsorptivity and the photocatalytic activity of the FAp-TiO_2 in the optimum conditions were investigated using the butyric acid and trimethylamine as model solutions. Consequently, the FAp-TiO_2 could obtain higher adsorptivity and photocatalytic activity for trimethylamine, rather than the uncoated TiO_2. 続きを見る

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