Impact of instrument and experiment parameters on reproducibility of ultrahigh resolution ESI FT-ICR mass spectra of natural organic matter

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Organic Geochemistry 41 (2010): 725-733, doi:10.1016/j.orggeochem.2010.05.017.Natural dissolved organic matter (OM) is a complex heterogeneous mixture of compounds that have defied traditional characterization using standard analytical methods. Electrospray ionization mass spectrometry, particularly ultrahigh resolution mass spectrometry, has provided a new platform for compositional assessment of this important pool of the Earth’s reduced carbon. Here, we propose a framework for optimization of instrument and experiment parameters for high quality data acquisition using Fourier‐transform ion cyclotron resonance mass spectrometry (FT‐ICR‐MS). We report the impact of these parameters on reproducibility of peak detection and repeatability of peak height in replicate injections of Suwannee River fulvic acid (FA), a common terrestrial OM standard. In addition, we examine the variability in peak detection and peak height among different types of experimental replicates of dissolved OM derived from laboratory cultures of Candidatus Pelagibacter ubique, a ubiquitous marine α‐ proteobacterium.The National Science Foundation (Major Research Instrumentation program: OCE‐0619608 (E.B.K.), the Chemical Oceanography program: CAREER‐OCE‐0529101 (E.B.K.) and OCE‐0751897 (E.B.K. and S.J.G.)), the Marine Microbiology Initiative at the Gordon and Betty Moore Foundation (S.J.G.) and supporting funds from the WHOI Director of Research (E.B.K.)