Recently several attempts have been made to adapt polarographic methods to the study of molten salt systems. The principal need has been for an physico-chemical procedure which could be operated in situated temperature up to 1000°C. The technique contains several difficulties different from the case of ordinary polarography in aquous solution, due to high temperature, consequently severe corrosion, and anhydrous medium. Such technique and its recent process are clescrihed and some of the anomalous features of the results are discussed.

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The anodic stripping voltammetry, which has been developed recently, are reviewed with 8 references.The anodic stripping methods involve the depositing metal ions electrolytically on an electrode and the oxidizing the metals electrochemically.These are very sensitive for the determination of trace amounts of metal ions, and under favorable conditions have a lower limit of determination on the order of 10^-9M.In these analytical applications, all of these methods involve the electrodeposition of a metal from a dilute solution by some reproducible procedures.The amount so deposited then bears a known relation to the concentration of the metal ion in the solution and is measured in terms of an electrical signal produced by its complete or partial dissolution at more anodic potentials.The electrodes have been used in various types, e.g., mercury pools, hanging mercury drops and amalgamated platinum electrodes.W.Kemula and co-workers, have used the electrode and cell like Fig.1 in their experiments of anodic stripping voltammetry.Since in the application of the hanging mercury drop electrode to analytical determination of trace metals, the very dilute solutions were used, no mutual interaction of metals in mercury drop electrode was observed even in the presence of more than one metallic species. Application of this method to the study on the formation of intermetallic compounds can be illustrated with reference to the nickel-zinc system.In Fig.2 curves of dissolution of amalgams formed at the hanging mercury drop electrode are given.Calomel film on the hanging mercury drop electrode did not interfere with Ni oxidation.The intermetallic compo-unds do not form at concentration less than 10^-5M.W.Kemula and his co-workers have studied on the determination of Cu, Bi, Sb, Pb, Sn, In and Cd in highly pure zinc.It consists of a preliminary 3-5 minutes electro-lytic concentration of the metals on the hanging mercury drop electrode, and subsequent recording of the oxidation currents of the amalgams formed.When no chemical separation is necessary the total time of analysis does not exceed 90minutes.The lowest concentrations found in the zinc samples analyzed were:6.4×10^-5% Pb, 8.2×10^-6% Cd, 2×10^-5% Sb and 6.8×10^-4% In.(Fig.3, 4 and Table I).W.Kemula and his co-workers have studied on the rapid determination of Cu, Pb and Cd in U compounds (10^-6% Cd and 10^-5% Cu and Pb).The analysis time, dependent on the compound being analysed, is approximately 1-2 hours. The precision is about ±10%.The determination is performed in carbonate solution in which the UO₂(CO₃)₃^4- complex is reduced at -1.0V., which does not influence the reduction of ions with more positive reduction potentials.An investigation was made of the concentration range in which it was supposed that Cu, Pb and Cd carbonates would precipitate and interfere with the determination.This type of interference was observed when the concentrations of Cu exceeded 10^-6M and that of Cd and Pb exceeded 10^-5M.(Fig.5 and Table II.).R.Neeb has studied on the principle of the anodic amalgam voltammetry and the determination of small amounts of lead, cadmium, bismuth and thallium.After the electrolytic separation of metals at amalgamated platinum electrode and rapid resolution of the amalgams at more anodic potentials, reproducible results can be obtained for trace amounts of metals under controlled conditions by measuring the peak heights on the current-voltage curve.Detailed procedures for the determination of trace amounts of Pb, Cd, Li, and Tl are given.A.G.Stromberg and his co-worker used a platinum wire cathode, on which the mercury from saturated Hg(NO₃)₂solution was deposited, in the determination of 10^-8to 10^-7M Pb²⁺in 0.1N KCl.The s

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There was traced an analogy between polarographic methods and measurements of flow rate in a flowing system, which is composed of a hydraulic reservoir, pumps and a piston whose plunger can control the opening of pump-exits. A flow into its cylinder corresponds to the condenser current and a pumped flow corresponds to the electrolytic current. With these analogues DC, AC, SW and RF polarographic methods may be explained. But for current controlled polarography and Heyrovsky-Forejt oscillographic polarography the further composition of flowing system is necessary.

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　交流ポーラログラフ法で記録されるピークの高さは,関与する電極反応の可逆度に依存する神原,松田によつて導入された理論によると,電極―溶液界面のFaradaic Admittrnccは(1)式で与えられる.ここでI_Acは交流電流の振巾,Δは交番電圧の振巾,qは電極表面積,ωは角速度,κ=0.627m^2/3t^I/6はよく知られているIlkovic factor,-di/dEは古典ポーラログラムの微分曲線である.可逆度は(2)式の様なパラメーターλに支配されている.、ここでkとkは還元と酸化の電極反応速度定数であり,D_oととD_Rは酸化体と還元体の拡散定数である.関数f(λ,ω)は(3)式で定義される.還元体の初濃度が0に等しいときは(4)式となり,Ilkovic理論により(5)式を用いると,(6)式をうる.yが実験的に測定出来ると,可逆度に関する関数f(λ,ω;)は次の様にして求めることが出来る.交流電流が最大値を示す半波電位での変数λを碗としよう.それから一次近似として(7)式がえられる.k_sは標準電位での速度定数である.この様に一定周波数の場合での関数f(λ,ω;)は(8)式で簡単に決められる.log f (λ,ω;)とlog(λ/√ω;)の変化はFig.1に示される.勾配1及び0の2直線は,破線で示される理論曲線の漸近線である.交点はf(λ,ω;)=1及びλ/√ω;=1に相当する.A.C.及びD.C.ポーラログラフ法に於ける波高は,柳本製A.C.ポーラログラフ(Type PA-102)で測定し,ポーラログラム例はFig.2に示す.滴下時間t_Ac及びt_Dcは,それぞれ交流波の頂点電位及び直流階段の高い平滑部で測定した.Randlcs,Somertonによつて報告されているk_sの値を用いるとlog xは計算出来,Fig.1.に示される様にlog x対log yの図にプロットされる.実験結果はTable 1.に要約される.Fig.1に示した直線はlog y=log x+6.72で示されることがわかつたA.C.ピークの高さを反応速度定数との対応性は千田,千出及び館によつて実験的に見出されていたが,現在の方法で反応速度定数を容易に決定することが出来る.1M NaOH中のZn⁺⁺を用いての実験ではlog yz_n=0.53であり,これからxz_n=6.46×10^-7をうる(標準としてHClO₄中のBi⁺⁺⁺のデーターを用いてx_Bi=1.83×10^-6がえらばれた).復極剤の濃度と水銀流出速度は一定に保たれるので,計算によりk_s=7.4×10^-5cm/sec(for Z_n²⁺ in 1M NaOH)となる.　可逆度の関数f(λ,ω;)がA.C.ポーラログラフ法のピークの高さを決定するということは,理論的に予想される.標準電位での反応速度定数値についてはよく一致することが実験的に立証された.D.C.波高と一緒にA.C.波高を測定すればlog yの値を定めることが出来,それに相当するκ又はλ/√ω;の値を決定することが出来る.しかしながらこの方法の第1の困難性はA.C.波高が濃度とよく比例する濃度範囲はD.C.ポーラログラフ法に於ける範囲より低い事である.それにもかかわらず,この方法は標電位での反応速度定数ksを計算するのに非常に簡単で迅速な方法を提供している.2,3の場合に於いては,電極反応に先行する化学反応があるということが知られている.その為に本法によつてえられる値は,簡単な電極反応が行われる場合に等価な速度定数であるということが出来よう　以上を要約するに交流ポーラログラフ法の波高と反応速度定数との関係が,神原,松田が提出した理論に基づいて実験的に研究された.A.C.波高は,可逆度関数によつて変化することが見出され,標準電位での電極反応速度定数K_sを計算する新しい簡単な迅速な方法が提出された.

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