Efficiency of methanol:Water solutions for metribuzin extraction from selected soils

Abstract

Extraction efficiency for metribuzin [4-amino-6-(l,l-dimethylethyl)-3-(methylthio)-l,2,4-triazin-5(4H)-one] from soil was evaluated using four solutions of methanol:water at ratios of 1:1, 7:3, 4:1, and 1:0 v/v. Two concentrations of metribuzin (0.216 and 2.44 ug/ g soil, unlabeled and I4 C-metribuzin, respectively) were added to surface and subsurface samples of a Dundee silt loam soil. Although the differences in extraction efficiencies were slight due to differences in methanol:water ratios, the metribuzin recovery varied with soil depth. Less metribuzin was recovered from surface soil extracted with 1:1 and 1:0 methanol:water solutions when compared to 7:3 and 4:1 solutions (80 and 81% vs 89 and 88% recoveries, respectively). About equal quantities, 81 to 85%, were recovered from the subsurface soil. Three extraction shaking times (0.5 h followed by another 0.5 h; 4 h:4 h; and 24 h:24 h) were also evaluated using the 4:1 extractant. No recovery differences were observed between the 0.5 h and 4 h shaking times. However, significantly higher recoveries occurred in both the surface and subsurface soil with 24 h shaking. The efficiency of this method was also determined on Eustis loamy sand, Sharkey clay, and Dorovan muck soils of diverse physical and chemical properties. The 4:1 extracting solution consistently 1.

Supercritical Fluid Extraction from Soil and HPLC Analysis of Cyanazine Herbicide

“…Conventional Extraction. Methanol and aqueous methanol have been reported to be very effective for extraction of triazines from soil (e.g., Cotterill, 1980;Locke et al, 1990). Soxhlet extraction with methanol/ water (1:1) (Benyon, 1972;Blumhorst and Weber, 1992) and extraction with acetonitrile/water (8:2) (Sirons et al, 1973) have been used for cyanazine extraction from soil.…”