|Barber, B - UNIVERSITY OF MINNESOTA|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 1999
Publication Date: N/A
Technical Abstract: The objective of this study was to determine the effect of supercritical fluid CO2 (SF-CO2) density and soil water content on supercritical fluid extraction (SFE) of selected pesticides from soil. 14C-labeled isofenphos and triadimefon were extracted from two Minnesota soils, Webster clay loam and Waukegon silt loam, at two soil water contents (3 percent and 12 percent) using two SF-CO2 densities (0.3 g ml-1 and 0.9 g ml-1). Quantitative recoveries of both pesticides (> 99 percent) were obtained under conditions of higher density and greater water content, while recoveries from drier soil using low density were poor (0.4 - 13 percent). At high density, water content had a greater effect on triadimefon extraction than for isofenphos extraction, particularly from clay loam soil. These results show the importance of considering soil water content when developing and optimizing SFE methods for extraction of different classes of pesticides from soils with different physical and chemical properties.