An investigation of the preparation and use of low-capacity anion exchangers in single-column ion chromatography

摘要

The preparation and uses of strong-base anion exchangers of low capacity are reviewed. A new adaptation of known reactions is presented for the reproducible preparation of Type I anion exchangers of low capacity and it is explored in some detail. The resins are based on the macroreticular copolymer known as XAD-1. It is shown that the same reaction scheme may be used on any porous styrene-divinylbenzene copolymer;Procedures are described for the preparation of twelve other strong-base resins with various structural differences in the quaternary ammonium functional group. These resins are then evaluated to determine the effect of chemical structure on selectivity for a number of common monovalent and divalent anions. It is shown that the structure of the quaternary ammonium ion has a definite effect on selectivity. It is also shown that surface modification can affect selectivity. The implications for single-column ion chromatography are discussed and some examples are given where a change in the chemical structure of the functional group is of practical value in the separation of anions;The factors influencing the choice of an eluent acid are outlined and it is shown that some acids are better than others on the basis of their lack of interaction with the copolymer matrix; (\u271)DOE Report IS-T-1082. This work was performed under Contract W-7405-eng-82 with the Department of Energy.