title: In-vitro estimation of bioaccessibility of chlorinated organophosphate flame retardants in indoor dust by fasting and fed physiologically relevant extraction tests.
abstract: This paper reports the evaluation of in-vitro physiologically relevant extraction tests for ascertainment of the bioaccessible fractions of emerging flame retardants from indoor dust in the gastric and gastrointestinal compartments. Standardized bioaccessibility tests under both fasting (UBM-like test) and fed (FOREhST test) conditions simulating the macronutrient composition of an average child diet were harnessed for investigation of the oral bioaccessibility of chlorinated organophosphate esters, namely, tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP) and tris(1,3-dichloro-2-propyl) phosphate (TDCP), in household and automobile cabin dust samples with varying concentration levels of contaminants. Minimal processing of the biomimetic extracts (only protein precipitation using acetonitrile) was proven feasible by analysis with liquid chromatography-mass spectrometric detection (LC-MS/MS). An inversely proportional relationship was identified between log Kowand oral bioaccessibility concentrations for TCEP, TCPP and TDCP in both dust samples with maximum bioaccessibility fractions for TCEP within the range of 50-103%. Non-bioaccessible fractions were determined by matrix-solid phase dispersion. Limits of quantification of LC-MS/MS in surrogate digestive fluids ranging from 0.4-0.8ng/mL suffice for determination of freely dissolved fractions of the two less hydrophobic species. Our results indicate that lipophilic food commodities used under fed-state gastrointestinal extraction conditions do not increase availability of TCEP, TCPP and TDCP in body fluids, and therefore conservative conditions in human health risk explorations for the target moderately polar flame retardants might be obtained with simplified tests under fasting conditions. This also holds true for the UBM/FOREhST bioaccessibility data for SRM 2585 (organic contaminants in house dust). Estimated average daily intake doses for toddlers incorporating oral bioaccessibility data afforded body burdens for the three chlorinated alkyl phosphates of ca. 3000 to 700 times below reference dose values, which indicate that long-term exposure to chlorinated organophosphate esters via accidental ingestion of indoor dust does not pose health risks to toddlers.
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Sciences, IIAA - Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain. Electronic address: jb.quintana@usc.es.
authors.forename: José Benito
authors.initials: JB
authors.lastname: Quintana
authors.affiliation: FI-TRACE Group, Department of Chemistry, Faculty of Science, University of the Balearic Islands, Carretera de Valldemossa km 7.5, E-07122 Palma de Mallorca, Illes Balears, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Rosende
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Sciences, IIAA - Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Montes
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Sciences, IIAA - Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Tania
authors.initials: T
authors.lastname: Rodríguez-Álvarez
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Sciences, IIAA - Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Rodil
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Sciences, IIAA - Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Cela
authors.affiliation: FI-TRACE Group, Department of Chemistry, Faculty of Science, University of the Balearic Islands, Carretera de Valldemossa km 7.5, E-07122 Palma de Mallorca, Illes Balears, Spain. Electronic address: manuel.miro@uib.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Miró
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D001682:Biological Availability; D004063:Digestion; D004391:Dust; D004435:Eating; D005215:Fasting; D005411:Flame Retardants / Q000032:analysis*; D005750:Gastric Juice / Q000737:chemistry; D006801:Humans; D008954:Models, Biological; D009943:Organophosphorus Compounds / Q000032:analysis*; D012463:Saliva / Q000737:chemistry
chemical_list: D004391:Dust; D005411:Flame Retardants; D009943:Organophosphorus Compounds
keywords: Bioaccessibility; Dust; Gastrointestinal extraction; Ingestion; Liquid chromatography-mass spectrometry; Organophosphate flame retardants