Determination of phthalate esters in seawater of Chabahar Bay using dispersive liquid-liquid microextraction coupled with GC-FID

Abstract

Phthalate esters (PEs), a group of environmental pollutants which are possibly carcinogenic to humans, have been detected in seawater. Seven PEs in seawater were quantitatively determined by using gas-chromatography flame ionizing detection after executing dispersive liquid-liquid microextraction. The suggested method is optimized for microextraction and determination of PEs in artificial sea water. Factors affecting the microextraction procedure such as the type and volume of extracting and dispersive solvents (carbon tetrachloride, 20 μL; methanol, 0.5 mL), extraction time and pH (7) were investigated. Under optimum conditions, the limit of detection of the analytes were obtained between 0.04 and 4.52 μg·L⁻¹, and linearity and linear range were of 0.999 ≥ R² ≥ 0.994 and 10–560 μg·L⁻¹ respectively. Enrichment factors were found in the range of 761–827 fold, while the relative standard deviations of the analytes were between 0.17 and 7.5% (n = 6) for real sea water samples. Using this method, total PEs content of seawater from several locations in Chabahar Bay (the southeast part of Iran) was estimated 2.33–90.45 μg·L⁻¹.

Highlights:

• PEs in seawater were analyzed by gas chromatography FID detection.

• Dispersive liquid-liquid microextraction was used to preconcentrate trace amounts of PEs.

• Parameters affecting DLLME efficiency were optimized for seawater samples.

• Performance of the method in extraction of PEs from the seawater of Chabahar bay was investigated.