title: Evaluation of a low-cost commercially available extraction device for assessing lead bioaccessibility in contaminated soils.
abstract: The U.S. EPA's in vitro bioaccessibility (IVBA) method 9200.1-86 defines a validated analytical procedure for the determination of lead bioaccessibility in contaminated soils. The method requires the use of a custom-fabricated extraction device that uses a heated water bath for sample incubation. In an effort to improve ease of use, increase sample throughput, and reduce equipment acquisition and maintenance costs, an alternative low-cost, commercially available extraction device capable of sample incubation via heated air and end-over-end rotation was evaluated. An intra-laboratory study was conducted to compare lead bioaccessibility values derived using the two extraction devices. IVBA values were not statistically different (α = 0.05) between the two extraction devices for any of the soils (n = 6) evaluated in this study, with an average difference in mean lead IVBA of 0.8% (s.d. = 0.5%). The commercially available extraction device was able to generate accurate lead IVBA data as compared to the U.S. EPA's expected value for a National Institute of Standards and Technology standard reference material soil. The relative percent differences between high and low IVBA values for each soil, a measure of instrument precision, were also not statistically different (α = 0.05) between the two extraction devices. The statistical agreement of lead IVBA values observed using the two extraction devices supports the use of a low-cost, commercially available extraction device as a reliable alternative to a custom-fabricated device as required by EPA method 9200.1-86.
authors.affiliation: U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Research Triangle Park, 109 T.W. Alexander Drive, Mail Code D205-05, Durham, NC 27711, USA. nelson.clay@epa.gov
authors.forename: Clay M
authors.initials: CM
authors.lastname: Nelson
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gilmore
authors.forename: M
authors.initials: M
authors.lastname: Harrington
authors.forename: Kirk G
authors.initials: KG
authors.lastname: Scheckel
authors.forename: Bradley W
authors.initials: BW
authors.lastname: Miller
authors.forename: Karen D
authors.initials: KD
authors.lastname: Bradham
mesh_terms: D004784:Environmental Monitoring / Q000191:economics / Q000295:instrumentation*; D004867:Equipment Design; D007854:Lead / Q000032:analysis* / Q000302:isolation & purification; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D012987:Soil; D012989:Soil Pollutants; D007854:Lead