SOXHLET AND MICROWAVE EXTRACTION IN DETERMINING THE
BIOACCESSIBILITY OF PESTICIDES FROM SOIL AND MODEL SOLIDS
1
Barbara K. Kramer and 2P. Barry Ryan
1
Department of Chemistry, Emory University, Atlanta, GA 30322; 2Rollins School of Public
Health, Emory University, Atlanta, GA 30322; 1Phone: (404) 727-9259, 1E-mail:
bkram01@emory.edu; 2Phone: (404) 727-3826, 2E-mail: bryan@sph.emory.edu.
The inadvertent ingestion of contaminated soil can be an important source of
pesticide exposure, especially in young children. The actual level of a pesticide that is
available for absorption into a biological system may be much lower than the overall
contamination level due to the interaction of each chemical with the solid matrix. This
bioaccessibility is dependent on characteristics of the chemical species as well as the soil
type and residence time of the compound in the soil. In an effort to improve understanding
of this phenomenon, we report a comparison of the recoveries of pesticides spiked into
three model solids, as well as soil using different analytical extraction techniques,
microwave assisted extraction (MAE), and Soxhlet extraction. The efficiencies of these
techniques are further compared to the results of a physiologically based extraction test
(PBET) that estimates the bioaccessibility of each compound to examine the potential use
of each extraction technique in bioavailability studies.
Key words: bioaccessibility, pesticides, soil, extraction