TY - JOUR

T1 - Determining the bioavailability of benzo(a)pyrene through standardized desorption extraction in a certified reference contaminated soil

AU - Posada-Baquero, R.

AU - Semple, K.T.

AU - Ternero, M.

AU - Ortega-Calvo, J.-J.

PY - 2022/1/10

Y1 - 2022/1/10

N2 - There is a strong need for certified reference materials in the quality assurance of nonionic soil contaminant bioavailability estimations through physicochemical methods. We applied desorption extraction, a method recently standardized as ISO16751, to determine the bioavailable concentration of the most commonly regulated polycyclic aromatic hydrocarbon (PAH), benzo(a)pyrene (BaP), in the reference industrial soil BCR-524 with a certified BaP total concentration of 8.60 mg kg−1. This concentration represented BaP levels found in many PAH-polluted soils. The method, based on single-point extraction of the analyte desorbed into the aqueous phase by a receiving phase (Tenax or cyclodextrin), was applied ten times. The data fulfilled highly demanding quality criteria based on recovery and repeatability. The bioavailable BaP concentration detected through Tenax extraction, 1.82 mg kg−1, was comparable to bioavailable concentrations determined in field-contaminated soils and to environmental quality standards based on previously observed total BaP concentrations. There was good agreement (Student's t-test, P ≤ 0.05) with the bioavailable BaP concentration determined by cyclodextrin extraction (1.53 mg kg−1). The methods were extended to four other certified 4- and 5-ringed PAHs for comparative purposes. We suggest ways of improving of the ISO16751 standard related to further systematic assessment of the Tenax-to-soil ratio and incorporation of mass balances. Furthermore, BCR-524 is suitable for quality-assurance protocols with these methods when used in site-specific risk assessments of PAH-polluted environments.

AB - There is a strong need for certified reference materials in the quality assurance of nonionic soil contaminant bioavailability estimations through physicochemical methods. We applied desorption extraction, a method recently standardized as ISO16751, to determine the bioavailable concentration of the most commonly regulated polycyclic aromatic hydrocarbon (PAH), benzo(a)pyrene (BaP), in the reference industrial soil BCR-524 with a certified BaP total concentration of 8.60 mg kg−1. This concentration represented BaP levels found in many PAH-polluted soils. The method, based on single-point extraction of the analyte desorbed into the aqueous phase by a receiving phase (Tenax or cyclodextrin), was applied ten times. The data fulfilled highly demanding quality criteria based on recovery and repeatability. The bioavailable BaP concentration detected through Tenax extraction, 1.82 mg kg−1, was comparable to bioavailable concentrations determined in field-contaminated soils and to environmental quality standards based on previously observed total BaP concentrations. There was good agreement (Student's t-test, P ≤ 0.05) with the bioavailable BaP concentration determined by cyclodextrin extraction (1.53 mg kg−1). The methods were extended to four other certified 4- and 5-ringed PAHs for comparative purposes. We suggest ways of improving of the ISO16751 standard related to further systematic assessment of the Tenax-to-soil ratio and incorporation of mass balances. Furthermore, BCR-524 is suitable for quality-assurance protocols with these methods when used in site-specific risk assessments of PAH-polluted environments.

KW - Bioavailability

KW - Certified reference soil

KW - Cyclodextrin

KW - Extraction

KW - Polycyclic aromatic hydrocarbons

KW - Tenax

KW - Anthracene

KW - Barium compounds

KW - Biochemistry

KW - Cyclodextrins

KW - Desorption

KW - Mineral oils

KW - Pyrene

KW - Risk assessment

KW - Soil pollution

KW - Benzo(a)pyrene

KW - Bioavailable

KW - Bioavailable concentrations

KW - Certified reference materials

KW - Contaminated soils

KW - Nonionic

KW - Polycyclic aromatics

KW - Soil contaminants

KW - Soils

U2 - 10.1016/j.scitotenv.2021.150025

DO - 10.1016/j.scitotenv.2021.150025

M3 - Journal article

VL - 803

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

M1 - 150025

ER -