Determination of phthalates in bottled water by automated on-line solid phase extraction coupled to liquid chromatography with uv detection

Abstract

An on-line solid phase extraction coupled to liquid chromatography with UV detection (SPE/LC-UV) method was automated by the multisyringe flow-injection analysis (MSFIA) system for the determination of three phthalic acid esters (PAEs). The PAEs determined in drinking water stored in polyethylene terephthalate (PET) bottles of ten commercial brands were dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP). C18-bonded silica membrane was used for isolation and enrichment of the PAEs in water samples. The calibration range of the SPE/LC-UV method was 2.5–100μgL−1 for DMP and DEP and 10–100μgL−1 for DBP with correlation coefficients (r) ranging from 0.9970 to 0.9975. Limits of detection (LODs) were between 0.7 and 2.4μgL−1. Inter-day reproducibility performed at two concentration levels (10 and 100μgL−1) expressed as relative standard deviation (%RSD) were found in the range of 0.9–4.0%. The solvent volume was reduced to 18mL with a total analysis time of 48min per sample. The major species detected in bottled water samples was DBP reaching concentrations between 20.5 and 82.8μgL−1. The recovery percentages for the three analytes in drinking water were 80–115%. The migration test showed a great variation in the sum of migrated PAEs level (10.2–50.6μgL−1) among the PET bottle brands analyzed indicating that the presence of these contaminants in the plastic containers may depend on raw materials and the conditions used during their production process.