ISSN:
0935-6304
Keywords:
Supercritical fluid extraction
;
cGC-NPD herbicides
;
CO2 modifiers
;
Incurred herbicides and metabolite extraction
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
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 Co2 modified 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 and ca. 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.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jhrc.1240190104
