Effect of temperature, collection mode, and modifier on the supercritical CO₂ extraction of dicofol residues from fish samples

Toxicity evaluation of Dicofol to Astyanax bimaculatus schubarti , a characteristic fish species living in tropical rivers and lakes was carried out through LC 50 – 96 Hours. These experiments were performed under laboratory controlled conditions with atmospheric air flow and dilution water at 25°C in the static mode, supercritical fluid extraction (SFE) with pure CO 2 and CO 2 modified with hexane and methanol were used at 50, 70, 80, and 100°C and 300 atm. Several collection modes were studied to extract Dicofol from fish samples. The extraction efficiencies were directly comparedd with those obtained after 8 h of Soxhlet extraction using the same clean‐up with Florisil and analysis by HRGC/ECD and HRGC/MS as a confirmatory analytical technique. The SFE recoveries at temperatures lower than 80°C were typically lower than soxhlet recoveries; however a temperature increase enhanced the efficiency of SFE. The results showed that under certain conditions, supercritical fluid gave higher extractio power (extracted 11 % more pesticide), shorter extraction time, and lower solvent consumption than Soxhlet, thus affording an excellent alternative to the conventional method for extracting Dicofol from fish sample.