Determination of phthalates in water samples using polystyrene solid-phase extraction and liquid chromatography quantification

A method for the determination of butylbenzylphthalate (BBP) and di-(2-ethylhexyl)phthalate (DEHP) in water samples has been developed and validated. The phthalates were extracted from water samples using solid-phase extraction on polystyrene columns. Quantification was achieved by gradient elution reversed-phase liquid chromatography with UV-detection at 280 nm. The method has been validated for BBP and DEHP in the concentration range of 1-200 and 0.1-10 mu gl(-1), respectively The internal standards were dibutylphthalate (DBP) and di-n-octylphthalate (DnOP). The within-day repeatability of BBP and DEHP were 0.5-1.5 and 2.0-6.5% relative standard deviation (RSD), respectively. The accuracy determined as recovery was 99-104% for both compounds. However, DEHP can only be determined with high accuracy in the range 0.1-3 mu gl(-1). The solubility of DEHP appears to be the limiting factor. The between-day repeatability was 1.1 and 4.2% RSD at the 1 mu gl(-1) level for BBP and DEHP, respectively. The concentration limits of detection were 0.05 (BBP) and 0.1 (DEHP) mu gl(-1). (C) 2000 Elsevier Science B.V. All rights reserved.