Fig. 2. Effect of extraction solvent (chlorobenzene) volume on the enrichment factors (EFs) of the studied PEs. Conditions: 5.0 mL water sample volume; 0.5 mL disperser solvent (acetone); different chlorobenzene volumes (10, 20, 30, 40 and 50 μL); 0.02 μg mL⁻¹ of each PEs.