著者
垣内 隆
出版者
日本ポーラログラフ学会
雑誌
Review of Polarography (ISSN:00346691)
巻号頁・発行日
vol.60, no.2, pp.99-109, 2014-09-24 (Released:2014-09-27)
参考文献数
22
被引用文献数
1 2

The criticism to the concept and use of single ion activity raised by de Levie (2010) has been examined. The lack of falsifiability in the concept of single ion activity, which he claims, led him to categorize the single ion activity as one of non-falsifiables, typified by the emperor’s new clothes (2012). However, his criticism is overeager, because the single ion activity can be estimated with a reasonable certainty, whose degree varies with a nonthermodynamic assumption employed, though. Electrochemistry is intrinsically nonthermodynamic, although in many of electrochemistry textbooks its cell voltage is correlated with the Gibbs energy of a redox reaction that would proceed in a homogeneous solution between the two redox couples, which are employed in the electrochemical cell. Ironically, such oversimplified understanding or picture of the nature of electrochemical cells partly justifies the criticism raised by de Levie. The obscurity associated with nonthermodynamic nature of electrochemical cells translates to the obscure interpretation of the Nernst equation in the form, E = E0 + (RT/F)ln(aOx/aRd), which has long been applied to a working electrode in electroanalytical chemistry. By focusing on this obscurity, it is possible not only to make our understanding of electroanalytical chemistry clearer but to design an electrochemical cell for less obscure, more reliable estimation of single ion activities.
著者
垣内 隆 山本 雅博
出版者
公益社団法人 日本分析化学会
雑誌
分析化学 (ISSN:05251931)
巻号頁・発行日
vol.65, no.4, pp.181-191, 2016-04-05 (Released:2016-05-10)
参考文献数
85
被引用文献数
4

適度な疎水性を持つイオン液体を塩橋に使用すると,濃厚KCl水溶液からなる塩橋では不可能であった低イオン強度水溶液のpHを正確に測定することができる.また,試料水溶液が疎水性イオンを含まなければ,pH標準緩衝液より高いイオン強度を持つ試料のpH測定にも,イオン液体塩橋は有望である.イオン液体塩橋は,水素イオンのみならずその他のイオンの単独イオン活量測定を広いイオン強度範囲で測定することを可能にするので,pH測定の実用的な観点のみならず,長年にわたる濃厚KCl水溶液塩橋を用いるポテンショメトリーの枠組みを越えた電解質溶液の研究が展望できる.