title: Inter-laboratory validation of bioaccessibility testing for metals.
abstract: Bioelution assays are fast, simple alternatives to in vivo testing. In this study, the intra- and inter-laboratory variability in bioaccessibility data generated by bioelution tests were evaluated in synthetic fluids relevant to oral, inhalation, and dermal exposure. Using one defined protocol, five laboratories measured metal release from cobalt oxide, cobalt powder, copper concentrate, Inconel alloy, leaded brass alloy, and nickel sulfate hexahydrate. Standard deviations of repeatability (sr) and reproducibility (sR) were used to evaluate the intra- and inter-laboratory variability, respectively. Examination of the sR:sr ratios demonstrated that, while gastric and lysosomal fluids had reasonably good reproducibility, other fluids did not show as good concordance between laboratories. Relative standard deviation (RSD) analysis showed more favorable reproducibility outcomes for some data sets; overall results varied more between- than within-laboratories. RSD analysis of sr showed good within-laboratory variability for all conditions except some metals in interstitial fluid. In general, these findings indicate that absolute bioaccessibility results in some biological fluids may vary between different laboratories. However, for most applications, measures of relative bioaccessibility are needed, diminishing the requirement for high inter-laboratory reproducibility in absolute metal releases. The inter-laboratory exercise suggests that the degrees of freedom within the protocol need to be addressed.
authors: ToxStrategies, Inc., 9650 Strickland Rd., Suite 103-195, Raleigh, NC 27615, USA. Electronic address: rhenderson@toxstrategies.com.
authors: Rayetta G
authors: RG
authors: Henderson
authors: Eurometaux, Avenue de Broqueville 12, 1150 Brussels, Belgium. Electronic address: verougstraete@eurometaux.be.
authors: Violaine
authors: V
authors: Verougstraete
authors: Oregon State University, Corvallis, OR 97331, USA. Electronic address: kim.anderson@oregonstate.edu.
authors: Kim
authors: K
authors: Anderson
authors: CECM, Adolfo Ibañez University, Diagonal Las Torres 2640, Peñalolen, Santiago, Chile. Electronic address: jose.arbildua@uai.cl.
authors: José J
authors: JJ
authors: Arbildua
authors: Duke University, 2200 West Main Street, Suite 400, Durham, NC 27705, USA. Electronic address: thomas.brock@duke.edu.
authors: Thomas O
authors: TO
authors: Brock
authors: ECTX bvba, Havenstraat 46/0.01, B-3500 Hasselt, Belgium. Electronic address: tony.brouwers@ectx.be.
authors: Tony
authors: T
authors: Brouwers
authors: Kirby Memorial Health Center, 71 North Franklin Street, Wilkes-Barre, PA 18701, USA. Electronic address: dcappellini@epix.net.
authors: Danielle
authors: D
authors: Cappellini
authors: European Copper Institute, 168 Avenue de Tervueren, 1150 Brussels, Belgium. Electronic address: katrien.delbeke@copperalliance.eu.
authors: Katrien
authors: K
authors: Delbeke
authors: KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-10044 Stockholm, Sweden. Electronic address: herting@kth.se.
authors: Gunilla
authors: G
authors: Herting
authors: ToxStrategies, Inc., 9650 Strickland Rd., Suite 103-195, Raleigh, NC 27615, USA. Electronic address: ghixon@toxstrategies.com.
authors: Greg
authors: G
authors: Hixon
authors: KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-10044 Stockholm, Sweden. Electronic address: ingero@kth.se.
authors: Inger
authors: I
authors: Odnevall Wallinder
authors: CECM, Adolfo Ibañez University, Diagonal Las Torres 2640, Peñalolen, Santiago, Chile. Electronic address: Patricio.rodriguez@uai.cl.
authors: Patricio H
authors: PH
authors: Rodriguez
authors: International Zinc Association, Avenue de Tervueren 168/Box 4, B-1150, Belgium. Electronic address: fvanassche@zinc.org.
authors: Frank
authors: F
authors: Van Assche
authors: Freie Universität Berlin, Promenadenstr. 16 A, D-12207 Berlin, Germany. Electronic address: wilrich@wiwiss.fu-berlin.de.
authors: Peter
authors: P
authors: Wilrich
authors: Nickel Producers Environmental Research Association, Inc., 2525 Meridian Parkway, Suite 240, Durham, NC 27713, USA. Electronic address: aoller@nipera.org.
authors: Adriana R
authors: AR
authors: Oller
mesh_terms: D001826:Body Fluids / Q000378:metabolism*; D006801:Humans; D007753:Laboratories / Q000592:standards*; D008670:Metals / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results
chemical_list: D008670:Metals
keywords: Alloys; Bioaccessibility; Bioelution; Classification; Inter-laboratory validation; Metals; Read-across; UVCBs