Assessing the aquatic toxicity of petroleum products: comparison of PETROTOX calculations and SPME-GC screening

Report No. 3/16: Using detailed two-dimensional chromatography (GCxGC) analysis of a set of petroleum product samples of Gas Oils, Residual Aromatic Extracts (RAE) and Bitumen categories, PETROTOX predictions have provided information to support revised category justification documents and enable the selection of “worst case” products in each category for ecotoxicity testing.

In addition, analysis of Water Accommodated Fractions (WAFs) of these product samples using Biomimetic Extraction (BE) with solid phase microextraction (SPME) fibres was used to confirm that SPME data correlates to Toxic Units predicted by the PETROTOX model using GCxGC compositional data, thereby strengthening the linkage between composition, SPME data and aquatic toxicity. This provides a technical basis for further use of SPME as a more practical characterization tool for addressing the influence of variation in substance composition on aquatic toxicity within petroleum product categories as SPME correlates well with PETROTOX calculations and consistent TU-dose response relationships between algae and daphnia are observed.

BE-SPME is shown to be a cost-effective approach to toxicity screening for petroleum substances, and thus an alternative method to enhance currently available ecotoxicity data sets, as well as complement predicted ecotoxicity using PETROTOX.