Prediction of the behaviour of organic pollutants using cloud point extraction

A preconcentration study based on the cloud point phenomenon was carried out for a set of triazine herbicides, three of them chloro-substituted and three of them methylthio-substituted. Concentration factors and recoveries were calculated as function of the percentage of the non-ionic surfactant Triton X-I 14 employed. From these values, obtained from a cloud point extraction (CPE) procedure, the distribution coefficient between the Triton X-114 micelles and water, K-c, prior to CPE was calculated for each triazine and related to the corresponding octanol-water partition coefficient, K-ow, In order to confirm the results obtained with the triazine herbicides, two sets of data from chemically different organic pollutants-organophosporous and chlorophenols-obtained from the literature were assessed, concluding that they display a similar behaviour to that of the triazine herbicides. This can be used to predict the CPE behaviour of other organic pollutants from their octanol-water partition coefficients. The K-c values were compared with the analyte concentration ratio in the surfactant-rich phase and aqueous phase (K-sa) with a view to obtaining a link between the analyte behaviour prior to and after cloud point extraction procedures. (C) 2003 Elsevier B.V. All rights reserved.