Thin-layer chromatography of inorganic ions II.—An examination of the behaviour of ion exchange resins as a stationary phase

Abstract

This paper presents a comparative study between the behaviour of inorganic ions on thin layers of anionic resins Amberlite CG 400 and cationic Amberlite CG 120, 200–400 mesh, employing, as eluent, watery solutions of HCl 37% RP, and the behaviour of the same ions, deduced from literature, for analogous techniques. The result of comparisons is mainly qualitative, in that the types of resins employed by various authors are not identical. The values of RF on layers of Amberlite CG 120 resin, H+ from, as function of HCl normality, used as eluent, are compared with the values of distribution coefficients Kd, for ion exchange columns, plotting values of RM vs. log Kd. Similar investigation is carried out, plotting values of RF on layers of anionic resin Amberlite CG 400, Cl− form, vs. eluent HCl normality and comparing them with values of RM on ion exchange paper and with those on silica gel impregnated with liquid exchanger Alamine 336, these last data obtained from literature. The result, for cationic resin, is that thin layer shows remarkable analogy with exchange column technique. For anionic resin, besides analogous results with those on ion exchange column, there is good agreement with chromatography on anionic exchange paper and on adsorbents impregnated with liquid anionic exchangers. Therefore, there is the possibility of employing the wellknown data on Kd, to transfer the separations on columns to thin layers. Vice versa the RF values, obtained on thin layer, may be used to predict values of Kd, on a column. However it is necessary to bear in mind the possibility of discrepancies associated with the peculiarity of the thin layer technique.