Passive Dosing Yields Dissolved Aqueous Exposures of Crude Oil Comparable to the CROSERF (Chemical Response to Oil Spill: Ecological Effects Research Forum) Water Accommodated Fraction Method

Authors

Gopal Bera, Texas A&M University
Thomas Parkerton, ExxonMobil Biomedical Sciences
Aaron Redman, ExxonMobil Biomedical Sciences
Nicholas Turner, Nova Southeastern UniversityFollow
Dorothy-Ellen A. Renegar, Nova Southeastern UniversityFollow
Jose Sericano, Texas A&M University
Anthony H. Knap, Texas A&M University

ORCID

0000-0003-1330-1278

Document Type

Article

Publication Title

Environmental Toxicology and Chemistry

ISSN

0730-7268

Publication Date

11-2018

Keywords

Water accommodated fraction, Passive dosing, Crude oil, PETROTOX

Abstract

The Chemical Response to Oil Spill: Ecological Effects Research Forum's water accommodated fraction procedure was compared with 2 alternative techniques in which crude oil was passively dosed from silicone tubing or O‐rings. Fresh Macondo oil (MC252) was dosed at 30 mg/L using each approach to investigate oil dissolution kinetics, which was monitored by fluorometry as estimated oil equivalents (EOEs). Subsequent experiments with each dosing method were then conducted at multiple oil loadings. Following equilibration, test media were analytically characterized for polyaromatic hydrocarbons (PAHs) using gas chromatography (GC)–mass spectrometry and dissolved oil using biomimetic solid‐phase microextraction (SPME). The results showed that equilibrium was achieved within 72 h for all methods. Measured PAH concentrations were compared with oil solubility model predictions of dissolved exposures. The concentration and composition of measured and predicted dissolved PAHs varied with oil loading and were consistent between dosing methods. Two‐dimensional GC compositional data for this oil were then used to calculate dissolved toxic units for predicting MC252 oil acute toxicity across the expected range of species sensitivities. Predicted toxic units were nonlinear with loading and correlated to both EOE and biomimetic SPME. Passive dosing methods provide a practical strategy to deliver and maintain dissolved oil concentrations while avoiding the complicating role that droplets can introduce in exposure characterization and test interpretation.

DOI

10.1002/etc.4263

Volume

37

Issue

11

First Page

2810

Last Page

2819

Comments

©2018 SETAC

NSUWorks Citation

Gopal Bera, Thomas Parkerton, Aaron Redman, Nicholas Turner, Dorothy-Ellen A. Renegar, Jose Sericano, and Anthony H. Knap. 2018. Passive Dosing Yields Dissolved Aqueous Exposures of Crude Oil Comparable to the CROSERF (Chemical Response to Oil Spill: Ecological Effects Research Forum) Water Accommodated Fraction Method .Environmental Toxicology and Chemistry , (11) : 2810 -2819. https://nsuworks.nova.edu/occ_facarticles/989.