Ion-exchange extraction of organic acids in water samples. Study of the influential factors and interactions

The objective is to concentrate organic acid traces in water samples. The i nfluence of several parameters and their interactions on the adsorption of organic acids on anion exchange resins was studied. A complete factorial de sign 2(4) was hence performed. The measured response corresponds to the max imal percolation volume and the studied parameters were the nature and the mass of the resin, the percolation flow-rate and the ionic strength of the analysed water. The results shown that the percolation flow-rare is signifi cant but not really important compared to the resin mass and to the nature of water. Indeed, the sample inorganic anions can compete with organic acid s. This adsorption competition appears to be more important when a macropor ous resin is used. A "gel-type" resin could he therefore better adapted to the extraction of organic acids in water samples.