Submitted to: Great Lakes Regional American Chemical Society Symposium
Publication Type: Abstract Only
Publication Acceptance Date: June 3, 2002
Publication Date: June 3, 2002
Citation: Koskinen, W.C. 2002. Extraction of pesticides and other toxic organic chemicals from soil. Great Lakes Regional American Chemical Society Symposium. p. 55. Technical Abstract: The determination of pesticides, particularly newer classes of pesticides, and other toxic organic chemicals in environmental samples presents challenging analytical problems. For instance, some of the newer classes of pesticides must be analyzed at trace levels; they can affect plant growth at concentrations of 0.1 g kg-1 (ppb). Analyses of these chemicals also can seldom be performed directly after extraction from soil because of the trace level of the chemical in the matrix compared to the amount of coextracted interfering substances. Polar solvents based on aqueous methanol and aqueous acetonitrile have been used routinely to extract pesticides and other toxic organic chemicals from soil that had chemicals applied up to 18 months previously. Small amounts of acid or base added to polar solvents can increase extraction efficiency for acidic and basic chemicals. However, there does not appear to be a universal extraction solvent. In an attempt to decrease organic solvent use and speed extraction, microwave-assisted solvent extraction (MASE) has been recently used for pesticide extraction from soil. Accelerated solvent extraction (ASE) uses a variety of solvents at high temperatures and pressures, but the solvent is not under supercritical conditions. Supercritical fluid extraction (SFE) with environmentally-friendly supercritical fluids such as CO2, is increasingly being used as an alternative extraction technique. In this talk, advantages and disadvantages of the some of the newer extraction techniques (i.e. MSAE, and accelerated solvent extraction) as compared to traditional organic solvent extraction will be discussed.