Characterization of dissolved organic matter in Lake Superior and its watershed using ultrahigh resolution mass spectrometry
Minor, Elizabeth C.
Steinbring, Carla J.
Kujawinski, Elizabeth B.
MetadataShow full item record
KeywordDissolved organic matter; Natural organic matter; Electrospray ionization; Fourier-transform ion cyclotron resonance mass spectrometry; Ultrahigh resolution mass spectrometry; Lake Superior; Van Krevelen diagram; Cluster analysis; Lakes
With the advent of ultrahigh resolution mass spectrometry, recent studies have begun to resolve molecular-level relationships between terrestrial and aquatic dissolved organic matter (DOM) in rivers, estuaries, mangrove swamps and their receiving oceans and lakes. Here, we extend ultrahigh resolution mass spectrometry techniques to Lake Superior, the largest freshwater lake in the world by area. Solid-phase extracted samples from the western arm of the lake and its watershed, including swamp, creek, river, lake-river confluence and offshore lake sites were compared using electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Results were analyzed using cluster analysis and van Krevelen diagrams. Chemical similarity appears related to hydrological proximity, terrestrial impact and flow conditions. For example, higher and lower flow samples from the same stream differ from one another. Toivola Swamp, Lake Superior, and the south shore river have diverse arrays of unique molecular formulae.relative to the north shore river and stream sampled in this data set. Lake Superior’s unique elemental formulae, relative to its watershed samples, are primarily in the lignin-like and reduced hydrocarbon regions of van Krevelen diagrams. ESI-amenable Lake Superior DOM also has a higher proportion of formulae containing nitrogen or sulfur relative to the other samples. The degree of overlap among formulae within our data set is consistent with previous ESI FT-ICR-MS characterization of terrestrial, estuarine and marine OM. There appears to be a conserved portion of formulae across natural OM samples, perhaps because these compounds are intrinsically refractory or because they are commonly generated as products of natural reworking processes.
Author Posting. © The Author(s), 2011. 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 43 (2012): 1-11, doi:10.1016/j.orggeochem.2011.11.007.
Showing items related by title, author, creator and subject.
Identification of possible source markers in marine dissolved organic matter using ultrahigh resolution mass spectrometry Kujawinski, Elizabeth B.; Longnecker, Krista; Blough, Neil V.; Del Vecchio, Rossana; Finlay, Liam; Kitner, Joshua B.; Giovannoni, Stephen J. (2009-04-30)Marine dissolved organic matter (DOM) is one of the most heterogeneous and largest pools of reactive carbon on earth, rivaling in mass the carbon in atmospheric carbon dioxide. Nevertheless, the molecular-level composition ...
Continuous summer export of nitrogen-rich organic matter from the Greenland Ice Sheet inferred by ultrahigh resolution mass spectrometry Lawson, Emily C.; Bhatia, Maya P.; Wadham, Jemma L.; Kujawinski, Elizabeth B. (2014-11)Runoff from glaciers and ice sheets has been acknowledged as a potential source of bioavailable dissolved organic matter (DOM) to downstream ecosystems. This source may become increasingly significant as glacial melt rates ...
Impact of instrument and experiment parameters on reproducibility of ultrahigh resolution ESI FT-ICR mass spectra of natural organic matter Kido Soule, Melissa C.; Longnecker, Krista; Giovannoni, Stephen J.; Kujawinski, Elizabeth B. (2010-04-09)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 ...