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Interaction in the methanol-water system has been studied (i) by the measurement of the mobile phase migration rate in mixed solvents of different composition and (ii) by the changes in chromatographic behaviour of hexacyanoferrate (III) and (II) anions produced by the solvent system. The formation of semi-, mono-, di-, and trihydrates of methanol has been observed. Paper chromatographic separation of hexacyanoferrate (III) and (II) anions has been achieved in the concentration range 85 to 65% (v/v) aqueous methanol, used as a mobile phase.

The potential of dimethyl sulphoxide (DMSO) as a mobile phase for chromatography on ready-for-use, thin-layers of silica gel, cellulose, and alumina has been examined with ferro- and ferricyanide anions, applied alone or as a mixture, as systems to be separated. The most satisfactory results, with very compact spots, are observed with silica gel thin-layers. The behaviour on cellulose layers is similar to that on paper, but the chromatographic spots are more compact in the former case, and therefore the separation there is much cleaner and more rapid. On alumina layers both the anions are highly adsorbed at the point of application, and ferrocyanide is rapidly oxidized to ferricyanide in the presence of DMSO. Alumina layers are therefore unsuitable for chromatography in the present system. The differentiative behaviour of DMSO towards the two closely similar anions is explained by considering the semipolar nature of the S−O bond, the molecular and electronic structure of DMSO, and the difference in ionic volume and ionic charge of the two anions.

The reduction of pertechnetate ion by dilute hydrochloric acid has been shown to be accelerated by the addition of bromide or iodide ions to the reaction mixture. At room temperature, concentrated hydrochloric acid requires an aging of two years to reduce pentavalent technetium, produced in the first stage byan instantaneous reduction of pertechnetate ion, to chromatographically pure technetium (IV). The rate of the reduction of pertechnetate ion by concentrated hydrochloric acid was found to be independent of the concentraton of ammonium pertechnetate in the range of 0.3–8 mg/ml.

The chromatographic behaviour of all alkali metal ions in phenol saturated with 2M hydrochloric acid has been examined by centrifugal and ascending chromatography. Separation with centrifugal development is about one hundred times more rapid than that obtained by the ascending technique. The shortest separation time achieved in these studies, six minutes, shows that centrifugal chromatography promises to be a useful rapid technique for the separation of short-lived fracium isotopes from a mixture of other alkali metals and for the routine analysis of alkali metals. The different degree of solvation of the cations by phenol, depending upon ionic size, is considered to be mainly responsible for the observed selective distribution of the alkali metal ions on the chromatogram.

Complex formation in acetone-water systems has been investigated by studying solvent migration rate and chromatographic behaviour of hexacyanoferrate (II) and (III). The formation of mono-, tetra-, and decahydrates of acetone has been observed, of which the tetrahydrate, also observable by other physical properties of the solvent mixture, is the most stable.