Chemical analysis of oil samples from the Gulf of Mexico and adjoining states from May 2010 to March 2014

This dataset contains oil chemistry data from the Deepwater Horizon (DWH) accident collected cooperatively by BP and the agencies, including agencies that serve as DWH natural resource damage trustees (Trustees). This report provides additional context for the oil chemistry dataset, including information about the collection, analysis, and organization of the data. This data posting differs from other recently published datasets relating to the Gulf of Mexico in several respects: This oil chemistry dataset focuses on information related to petroleum-related chemical constituents in oil samples and other matrices collected during studies focused primarily on the sampling of oil. Chemical compounds that are not present in Mississippi Canyon lease block 252 (MC252) oil (such as polychlorinated biphenyls, pesticides, and halogenated volatiles) are not included in this dataset. This dataset includes data from independent studies performed by BP consultants. BP has been working to produce and organize these independent data, and has engaged outside consultants to perform quality assurance and quality control (QA/QC) checks. As a result, these data have not previously been publicly accessible. This dataset combines results from 24 NRDA studies and 20 Response studies to create a unified data file. Before posting, extensive work was done independently by BP contractors to verify some aspects of the posted data (e.g., positional coordinates and field data). The chemical parameters provided in this data posting include: Parent and alkylated polycyclic aromatic hydrocarbons (PAHs) Saturated hydrocarbons (SHC) Total petroleum hydrocarbons (TPH), including parameters reported as total extractable material (TEM) and total extractable hydrocarbon (TEH) Benzene, toluene, ethylbenzene, and xylenes (BTEX) and other volatile hydrocarbons classified as paraffins, isoparaffins, aromatics, naphthenes, and olefins (PIANO) Geochemical biomarkers (sterane and triterpane), where available Dispersant markers Metals Total organic carbon. The chemical analyte lists are generally consistent between studies for the standard PAH, SHC, and BTEX compounds. However, portions of the dataset also include analysis of the extended PIANO volatile hydrocarbon list, TPH, or geochemical biomarkers. Additionally, NRDA PAH analyses include an extended list of PAHs (parent and alkylated PAHs) and non-PAH compounds (decalins, benzothiophenes, naphthobenzothiophenes, and related chemicals) that were not included in all of the Response analyses. This dataset includes data associated with natural field samples for oil and other sample matrices, along with the associated field-collected quality control samples, such as field replicates, equipment blanks, field blanks, and trip blanks. Laboratory duplicate sample data are provided, where available. MC252 control oils associated with chemistry analyses are part of a separate data posting (see Version History). No other laboratory quality control samples (e.g., laboratory blanks or spike samples) are included in this data posting. In addition to the detailed data file, a cross-tab summary version of these data is also provided (OilChemistry_O-05v01-01_xTab.zip) in Excel format. Results for each sample are presented in a single row with individual chemicals in columns. In addition, a summed concentration for total PAHs is included as “PAH50 Sum” and was calculated using 50 individual PAH results. This summary is provided to enable researchers to access this large data set in a more manageable format. A sample summary table in excel format is provided to summarize the number of analytical results for each parameter type for each sample.