Determination of selected phthalate esters compounds in water and sediments by capillary gas chromatography and flame ionization detector

Abstract

The presence of phthalate esters (PAEs) in the environment is not desirable and therefore, needs to be monitored. This study reports the first data on the concentration levels of PAEs in water and sediments of the Jukskei River catchment area, South Africa. The study was conducted during the summer and winter seasons of 2005. Liquid-liquid extraction (LLE) and Soxhlet extraction (SE) methods were optimized, evaluated and used to determine PAEs of interest in water (unfiltered and filtered) and sediments samples, respectively. Mean percentage recoveries in spiked doubly distilled water ranged from 100 ± 5.32 dimethyl phthalate (DMP) – 122 ± 0.46 di-2-ethylhexyl phthalate (DEHP) and 91.6 ± 1.93 diethyl phthalate (DEP) – 117 ± 4.80 dibutyl phthalate (DBP) in sediments. The concentration levels of PAEs studied in unfiltered environmental water samples were in the range of 0.04(± 0.00) (DMP) − 9.76(± 00.1) ng mL⁻¹(DEHP) for PAEs and from 0.09 (± 0.01) (DMP) – 4.38 (± 0.06) ng mL⁻¹(DEHP) for filtered environmental water samples. Concentration levels obtained in sediments were from 0.05 (0.00) (DMP) – 4910 (0.36) ng/gdw (DEHP). PAEs adsorbed on the sample bottle gave concentration levels of up to 0.10 (± 0.03) ng mL⁻¹for some samples and no analyte was detected (ND) in some cases Generally, concentrations obtained were below the water quality guideline values of United States Environmental Protection Agency (USEPA).

Keywords:

• Phthalates
• surface water
• sediments
• liquid-liquid
• Soxhlet extraction
• capillary gas chromatography and flame ionization detector

Acknowledgments

The authors would like to thank the Tshwane University of Technology and National Research Foundation (Scarce Skills Scholarship), South Africa, for financial assistance during this study.