Supercritical fluid extraction of atrazine and its metabolites from soil

Publisher Website
Google Scholar
Abstract
Soxhlet (methanol) and SFE extraction with carbon dioxide in the presence of modifiers at different temperatures (100–200°C) for the extraction of atrazine and its main metabolites from a soil sample were compared. The most effective extraction conditions for both atrazine and its metabolites (i.e.deethylatrazine and deisopropylatrazine) were Co2modified with 20% molar methanol‐trifluoroacetic acid (MeOH‐TFA) (TFA 0.65M in MeOH) at 100°C, leading to an extraction efficiency comparable with that of Soxhlet extraction with MeOH for atrazine andca.20% higher for its main metabolites. The relative standard deviation (RSD) of SFE was lower than that obtained by Soxhlet extraction, probably because of less interference in the cGC‐NPD determination. All the other modifiers evaluated (acetone, triethylamine, and methanol) were less effective than MeOH‐TFA for the extraction of atrazine and its metabolites from a soil sample, even at high molar concentrations (20%) and use of higher extraction temperatures (200°C). These results indicate the importance of matrix effects and the need of the selection of an appropriate modifier in order to obtain quantitative extractions by SFE.