Application of aqueous two-phase systems for the extraction of pharmaceutical compounds from water samples

Abstract In this study, the proposal was to use aqueous two-phase systems (ATPS) as a sample preparation technique for the determination of five pharmaceuticals, classified as emerging contaminants (EC): ibuprofen, paracetamol, ciprofloxacin, norfloxacin and amoxicillin. The evaluation of this study was performed through the partition coefficient (K) of each pharmaceutical by varying some parameters of the system, such as the pH value of the medium, the nature of the ATPS-forming electrolyte and polymer, the tie-line length (TLL), the system temperature and the mass ratio between the top and bottom phases of the ATPS. Values of K between 9.30 and 1150 were obtained for the five pharmaceuticals during the system optimization. The ATPS also proved to be efficient as a sample preparation technique in the partition of the studied pharmaceuticals when applied to water samples, including drinking water, surface water and filtered water from a water treatment plant. The values of the partition coefficients found in these complex samples ranged from 2.49 to 74.2.