Abstract:

Mesocosm experiments was conducted in June 2018 as part of ADDOMex-2 program funded through GOMRI. Marine oil snow samples were collected during the mesocosm experiments and analyzed by Fourier transform ion cyclotron resonance mass spectrometry coupled with electrospray ionization (ESI-FTICR-MS). The data summarized in this dataset will represent the raw m/z and intensity data directly from the instrument and the processed Microsoft Excel files used for analysis. At total, FTICR-MS results from six samples are included in this dataset.

Suggested Citation:

Waggoner, Derek, Hongmei Chen, and Patrick Hatcher. 2020. Mesocosom: Molecular level characterization of oil and aggregate oxidation products: MICROX, microbial oxidation and degradation of oil study (June 2018), FTICR-MS data. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-73gc-tq30

Purpose:

To investigate molecular level differences in natural dissolved organic matter (DOM) during microbial degradation of oil, DOM impacted by oil, and DOM impacted by oil and dispersant mixtures.

Data Parameters and Units:

Raw mass lists of m/z values (m = mass; z = charge of the ion) and their peak intensities (arbitrary units); Processed data with chemical molecular formulas, including: Index = molecular formula number, m/z = the measured mass to charge ratio of the identified peak (m= mass; z= charge of the ion), PeakHeight = the spectral intensity of the identified peak (in arbitrary units), Type = elemental formula type, CHO= formula containing carbon, hydrogen, and oxygen, CHON = formula containing carbon, hydrogen, oxygen, and nitrogen, CHOS = formula containing carbon, hydrogen, oxygen, and sulfur, CHONS = formula containing carbon, hydrogen, oxygen, nitrogen, and sulfur, CHOP = formula containing carbon, hydrogen, oxygen, and phosphorus, CHOSP = formula containing carbon, hydrogen, oxygen, sulfur, and phosphorus, CHONP = formula containing carbon, hydrogen, oxygen, nitrogen, and phosphorus; C = the number of C atoms in the assigned formula, H-1 = the number of H atoms in the ionic form of the assigned formula which corresponds to the measured m/z, H = the number of H atoms in the molecular form of the assigned formula, N = the number of N atoms in the assigned formula, O = the number of O atoms in the assigned formula, S = the number of S atoms in the assigned formula, P = the number of P atoms in the assigned formula, Exact mass = molecular weight.

Methods:

Marine snow from control samples and marine oil snow (MOS) from diluted chemically enhanced water-accommodated fraction (DCEWAF) samples were extracted with dicholoromethane (DCM) solvent. DCM extracts were diluted with methanol (MeOH) to a final ratio of MeOH:DCM as 2:1 (v/v), and analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) coupled with negative ion mode electrospray ionization (ESI), using an Apollo II ESI source coupled to a Bruker Daltonics 12 T Apex Qe FTICR-MS housed at the Old Dominion University COSMIC facility. Samples were infused into the instrument by a syringe pump at 2 uL/minute. Ions accumulated in the hexopole for 2.0 seconds before being transferred to the ICR cell. Analysis of 300 transients were coadded. Mass-to-charge data for peaks with signal-to-noise ratios greater than 3 were used to assign molecular formulas to peaks in each sample using an in-house Matlab (The MathWorks Inc., Natick, MA) program following the formula assignment rules established previously (Stubbins, Aron, et al. 2015; Knap, Anthony H., et al. 1986). Data file naming convention includes the mesocosm experiment number (M6), treatment (control, dilute chemically enhanced water accommodated fraction of oil = DCEWAF, water accommodated fraction = WAF), tank number (T3 tank or T12 tank), time since start (in days). For example, “M6_T3 Tank_T12_DCEWAF.csv” is the FTICR-MS for diluted chemically enhanced water accommodated fraction of oil at time 12 days from June 2018 Mesocosm 6 experiment. Mesocosm 6: The seawater used in the TeCOAST Mesocsom studies was collected in June 2018 from the Gulf of Mexico near Galveston, Texas and processed through a charcoal filter to remove large particles and debris. A plankton concentrate was collected nearby in Galveston Bay, Texas using a mesh size of 63 µm plankton net; 2 L of this “concentrate” was added to all mesocosm treatments, immediately prior to the start of the experiment. Four mesocosm tanks were treated in the same manner. The control tank was filled with the seawater directly from the storage tank of filtered seawater plus the added plankton concentrate. This seawater was also used to fill recirculating glass flumes (Wozniak, Andrew S., et al. 2019; Knap, Anthony H., et al. 1986; Wade, Terry L., et al. 2017) to make water accommodated fraction (WAF) and a chemically enhanced water accommodated fraction of oil (CEWAF). The WAF was prepared by mixing a Macondo surrogate Marlin oil into the seawater. Total mixing time from the start of oil addition to transfer to the mesocosms was 18 hours hrs ~ 24 hours hrs. The WAF was transferred to the WAF mesocosm tank and mixed. In order to make CEWAF, Corexit 9500 was mixed with Macando Surrogate oil in a ratio of 1:20 (Corexit to oil) and 24 mL of this mixture (2 mL to start, 2 mL after 1 hour, then 5 mL at ~ 2, 3, 4 and 5 hours total of 24 mL) of surrogate oil plus Corexit was added to 130 L of seawater and mixed for 18 hours . The CEWAF was transferred to the WAF mesocosm tank and mixed.

Instruments:

Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS); Apollo II ESI ion source coupled to a Bruker Daltonics 12 Tesla Apex Qe ESI FTICR-MS

Provenance and Historical References:

Stubbins, Aron; Robert G. Spencer, Hongmei Chen, Patrick G. Hatcher, Kenneth Mopper, Peter J. Hernes, Vincent L. Mwamba, Arthur M. Mangangu, Jose N. Wabakanghanzi, and Johan Six. Illuminated darkness: molecular signatures of Congo River dissolved organic matter and its photochemical alteration as revealed by ultrahigh precision mass spectrometry. Limnology and Oceanography. 2010, 55 (4), 1467−1477. Wozniak, Andrew S., Priscilla M. Prem, Wassim Obeid, Derek C. Waggoner, Antonietta Quigg, Chen Xu, Peter H. Santschi, Kathleen A. Schwehr, and Patrick G. Hatcher. Rapid degradation of oil in mesocosm simulations of marine oil snow events. Environmental Science & Technology. 2019, 53(7), 3441-3450. doi: 10.1021/acs.est.8b06532. Knap, Anthony H., Kathryn A. Burns, Rodger Dawson, Manfred Ehrhardt, and Karsten H. Palmork, Dissolved/dispersed hydrocarbons, tarballs and the surface microlayer: Experiences from an IOC/UNEP Workshop in Bermuda, December, 1984. Marine Pollution Bulletin. 1986, 17(7), 313–319. doi:10.1016/0025-326x(86)90217-1. Wade, Terry L., Maya Morales-McDevitt, Gopal Bera, Dawai Shi, Stephen Sweet, Binbin Wang, Gerado Gold-Bouchot, Antonietta Quigg, and Anthony H. Knap. A method for the production of large volumes of WAF and CEWAF for dosing mesocosms to understand marine oil snow formation. 2017, Heliyon 3(10): 3e00419. doi: 10.1016/j.heliyon.2017.e00419.

Individual Files: