Ion-exchange extraction of organic acids in water samples. Study of the influential factors and interactionsV. Desauziers1, C. Boucharat1 and P. Le Cloirec2
1 Laboratoire Génie de l'Environnement Industriel, École des Mines d'Alès, 6 avenue de Clavières, 30319 Alès Cedex, France
2 École des Mines de Nantes, D.S.E.E, 4 rue Alfred Kastler, BP. 20722, 44307 Nantes, Cedex 03, France
The objective is to concentrate organic acid traces in water samples. The influence of several parameters and their interactions on the adsorption of organic acids on anion exchange resins was studied. A complete factorial design 24 was hence performed. The measured response corresponds to the maximal 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-rate is significant but not really important compared to the resin mass and to the nature of water. Indeed, the sample inorganic anions can compete with organic acids. This adsorption competition appears to be more important when a macroporous resin is used. A "gel-type" resin could be therefore better adapted to the extraction of organic acids in water samples.
Key words: Organic acids / water analysis / ion exchange resin / adsorption / experimental design.
© EDP Sciences, Wiley-VCH 1998