title: Cloud point preconcentration of rather polar compounds: application to the high-performance liquid chromatographic determination of priority pollutant chlorophenols.
abstract: The potential of the cloud point methodology for the preconcentration of relatively polar compounds was studied using the non-ionic surfactant Triton X-114 and five EPA chlorophenols as test analytes. Analyte determination was performed using reversed-phase gradient LC with electrochemical and spectrophotometric detection. The amount of surfactant used is a critical variable in the preconcentration factor because it determines the extraction yield and the volume of surfactant-rich phase obtained. These values were determined as a function of the Triton X-114 concentration, together with the phase ratio, which allows prediction of the maximum preconcentration factor under given conditions.
authors: Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de Salamanca, Spain.
authors: L C
authors: LC
authors: Seronero
authors: M E
authors: ME
authors: Fernández Laespada
authors: J L
authors: JL
authors: Pavón
authors: B
authors: B
authors: Moreno Cordero
mesh_terms: D002138:Calibration; D002733:Chlorophenols / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D017830:Octoxynol; D011092:Polyethylene Glycols; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002733:Chlorophenols; D004785:Environmental Pollutants; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40