Limited water samples were collected from northern Gulf of Mexico waters in spring and summer of 2010 for further comparison with hypoxia hydrographic data and phytoplankton community composition
Rabalais, Nancy. 2015. Hydrocarbons in northern Gulf of Mexico offshore waters in 2010. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7JS9NCH
To determine the concentration of hydrocarbons at locations along the continental shelf to use in further comparison with hypoxia hydrographic data and phytoplankton community composition.
Data Parameters and Units:
Attribute_Label: Station Attribute_Definition: Producer defined station name corresponding to transect letter and station number within the transect. Lower numbers are closer to the coast, higher numbers are further offshore Attribute_Label: Date collected Attribute_Definition: Date samples were collected Attribute_Label: Latitude (decimal degrees) Attribute_Definition: Latitude of each transect in decimal degrees. Attribute_Label: Longitude (decimal degrees) Attribute_Definition: Longitude of each transect in decimal degrees. Attribute_Label: Depth (m) Attribute_Definition: Depth sample was collected. Zero indicates surface water collection using a bucket. Attribute_Label: Alkanes (ug/L) Attribute_Definition: Concentration of Alkane hydrocarbons in the water sample. Attribute_Label: Aromatics (ng/L) Attribute_Definition: Concentration of Aromatic hydrocarbons in the water sample.
Oil samples were analyzed by the Louis iana State University – Response and Chemical Assessment Team (LSU-RCAT). Samples were collected and analyzed using accepted standard operating and QA/QC procedures to prevent contamination and avoid sample degradation. The samples were analyzed by GC/MS (gas chromatography/mass spectrometry) to identify the normal and branched saturated hydrocarbons (from C10 to C35), the one- to five-ringed aromatic hydrocarbons and their C1 to C4 alkyl homologs, and the hopane and sterane biomarkers. All GC/MS analyses used an Agilent 7890A GC system configured with a 5% diphenyl/95% dimethyl polysiloxane high resolution capillary column (30 meter, 0.25 mm ID, 0.25 micron film) directly interfaced to an Agilent 5975 inert XL MS detector system. The MS was operated in the Selective Ion Monitoring (SIM) to maximize the detection of the target constituents unique to crude oil.
All GC/MS analyses used an Agilent 7890A GC system directly interfaced to an Agilent 5975 inert XL MS detector sys! tem.