Abstract:

Weathered oil transformation products were extracted from saltmarsh sediments. The acidic compounds were quantified, isolated, and characterized at the molecular level from 9 months to 10 years post-spill, in each acid fraction cataloged based on negative electrospray ionization (ESI) Fourier-transform ion cyclotron resonance (FT-ICR) Mass Spectrometry analysis.

Suggested Citation:

Huan Chen, Amy M. McKenna. 2019. Chemical characterization of acid compounds in salt marsh sediments by Electrospray ionization (ESI) Fourier-transform ion cyclotron resonance (FT-ICR) Mass Spectrometry analysis. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-mx2t-0830

Purpose:

Track the acidic compound of the weathered oil at the molecular level as a function of time.

Data Parameters and Units:

Main parameters: elemental formulae, aromaticity, and relative abundance. Reference (no oiling, RF), moderately (MD), and heavily (HV) oiled. The dataset consists of several excel files. Each excel file is organized with the following legend: Number of Peaks = Number of Peaks on Full Spectrum with signal magnitude greater than six times the baseline root-mean-square noise % R. A. = Percent Relative Abundance DBE = double bond equivalents - number of aromatic rings plus double bonds to carbon % R. A.(No Hits Discarded) = Percent Relative Abundance with Non-Classified Peaks Removed A. M. W. average = Relative abundance weighted average molecular weight A.W. average C# = relative abundance weighted average carbon number A.W. average DBE = average number of double bond equivalents A.W. average H/C = relative abundance weighted average hydrogen-to-carbon ratio A.W. average O/C = relative abundance weighted average oxygen-to-carbon ratio A.W. average N/C = relative abundance weighted average nitrogen-to-carbon ratio Sum R. A. = Sum of Relative Abundance for all mass spectral peaks RMS Error = Root Mean Square Error PosESI = Positive Electrospray Ionization NegESI = Negative ion electrospray ionization APPI = atmospheric pressure photoionization

Methods:

Negative electrospray ionization (ESI) Fourier-transform ion cyclotron resonance (FT-ICR) Mass Spectrometry analysis.The extraction methods are described in Chen et al., 2016.

Instruments:

The 21 tesla magnet was manufactured by Bruker Daltonics, Billerica, MA, USA, and the mass spectrometer combines a modified Velos Pro (ThermoFisher Scientific, San Jose, CA, USA) with an NHMFL-designed external linear quadrupole ion trap, quadrupole ion transfer optics, and novel dynamically harmonized ICR ion trap (DHC).

Provenance and Historical References:

Chen, H., Hou, A., Corilo, Y. E., Lin, Q., Lu, J., Mendelssohn, I. A., … McKenna, A. M. (2016). 4 Years after the Deepwater Horizon Spill: Molecular Transformation of Macondo Well Oil in Louisiana Salt Marsh Sediments Revealed by FT-ICR Mass Spectrometry. Environmental Science & Technology, 50(17), 9061–9069. doi:10.1021/acs.est.6b01156

Individual Files: