Comparison of microwave-assisted extraction of triazines from soils using water and organic solvents as the extractants

Microwave-assisted extraction (MAE) for the separation of atrazine, simazin e and prometryne from synthetic soil samples, using water and some organic solvents as the extractants, was studied in detail. The effects of the soil matrix, the soil moisture and the pH of the aqueous extraction system on t he MAE efficiency were also studied. It was found that the three triazines could be efficiently extracted under the conditions of 100% magnetron power output (600 W), the first grade of pressure (from 0.1 MPa to 0.5 MPa), 30 ml solvent and 4 min microwave heating with water or organic solvents, exce pt for prometryne with dichloromethane solvent for 1-4 g sandy loam sample. This interesting result was explained by triazines' solubility in water, t heir sorption properties in soils and the ability of the solvent to absorb microwave energy. Finally, evaluation of the extraction efficiency, as well as the treatment and determination of MAE extracts, suggested that water, as a cheap, safe and environmentally friendly solvent, can be a good altern ative to organic solvents, used as the extractants for MAE of triazines fro m soils. (C) 1999 Elsevier Science B.V. All rights reserved.