Optimization of extraction procedures for ecotoxicity analyses: Use of TNT contaminated soil as a model
- BRI, Montreal, Quebec (Canada)
- DREV, Courcelette, Quebec (Canada)
The environmental impact of energetic substances (TNT, RDX, GAP, NC) in soil is being examined using ecotoxicity bioassays. An extraction method was characterized to optimize bioassay assessment of TNT toxicity in different soil types. Using the Microtox{trademark} (Photobacterium phosphoreum) assay and non-extracted samples, TNT was most acutely toxic (IC{sub 50} = 1--9 PPM) followed by RDX and GAP; NC did not show obvious toxicity (probably due to solubility limitations). TNT (in 0.25% DMSO) yielded an IC{sub 50} 0.98 + 0.10 (SD) ppm. The 96h-EC{sub 50} (Selenastrum capricornutum growth inhibition) of TNT (1. 1 ppm) was higher than GAP and RDX; NC was not apparently toxic (probably due to solubility limitations). Soil samples (sand or a silt-sand mix) were spiked with either 2,000 or 20,000 mg TNT/kg soil, and were adjusted to 20% moisture. Samples were later mixed with acetonitrile, sonicated, and then treated with CaCl{sub 2} before filtration, HPLC and ecotoxicity analyses. Results indicated that: the recovery of TNT from soil (97.51% {+-} 2.78) was independent of the type of soil or moisture content; CaCl{sub 2} interfered with TNT toxicity and acetonitrile extracts could not be used directly for algal testing. When TNT extracts were diluted to fixed concentrations, similar TNT-induced ecotoxicities were generally observed and suggested that, apart from the expected effects of TNT concentrations in the soil, the soil texture and the moisture effects were minimal. The extraction procedure permits HPLC analyses as well as ecotoxicity testing and minimizes secondary soil matrix effects. Studies will be conducted to study the toxic effects of other energetic substances present in soil using this approach.
- OSTI ID:
- 367543
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9640%%289
- Resource Relation:
- Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
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