LC Enrichment, Separation, and Determination of Chlorophenols and Phenoxyacetic Acids on PRP-1

Abstract

Mobile-phase conditions for the enrichment of chlorophenols and chlorophenoxyacetic acids from large volumes of very dilute solutions and subsequent separation of the complex mixtures were evaluated. The stationary phase used in the LC procedure is a polystyrenedivinylbenzene copolymer, PRP-1, that provides good column efficiency and stability in strongly acidic and basic mobile phases, conditions which are optimum for enrichment and separation, respectively. Two enrichmentanalytical separation techniques are evaluated. One employs a semi-prep PRP-1 column (for larger loadings); the other a two-PRP-1 column system (for lower loadings) composed of a pre-column and an analytical column. Modification of the injector allows the enrichment-separation to be carried out in a continuous procedure.