Silica gel treated with a mixture of Aliquat 336 and Acid Alizarin Violet N and its application

Acid Alizarin Violet N is strongly extracted by chloroform solutions of Ali quat 336 by an ion-exchange mechanism. Relatively high concentrations of mi neral acids are required for its reextraction from the ion pair formed. By impregnation of silica with ion pairs composed of the cation of Aliquat 336 and the anion of the dye, a chelating sorbent for metal ions can be obtain ed. The sorbent prepared may be successfully used for the separation of mix tures of various metal ions by the column extraction chromatography techniq ue, for additional purification of sodium and potassium salts from the ions of heavy metals, and for the concentration of trace amounts of ions of var ious metals from aqueous solutions followed by their quantitative determina tion. The sorbent can be used repeatedly for the sorption and desorption of metal ions (especially those forming less stable complexes with the reagen t) after regeneration with solutions of chloric(VII) acid. The effect of hy drophobicity of the chelating reagent on the stability of its ion pair with the tetraalkylammonium cation has been confirmed. Acid Alizarin Violet N f orms less stable ion pairs with Aliquat 336 than the more hy drophobic Calm agit.