Selectivity in supercritical fluid extraction: recovery of pesticides from model matrices

Selected pesticides are spiked in an empty extraction thimble for use as a model system to study the solvating power of supercritical carbon dioxide and spiked in solid-phase sorbent materials to study the influences of matrix effects on the recoveries. Results from this study show that it is possible to identify supercritical fluid extraction conditions where the molecular structure of the analytes affect the extraction efficiency. The results also indicate that parameters other than solubility (e.g., volatility) have a marked influence on the extraction process, even under simplistic conditions (extraction from empty thimble).