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

Abstract

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 μg l −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 μg l −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 μg l −1 level for BBP and DEHP, respectively. The concentration limits of detection were 0.05 (BBP) and 0.1 (DEHP) μg l −1.