{"@context":{"content":"http:\/\/purl.org\/rss\/1.0\/modules\/content\/","dc":"http:\/\/purl.org\/dc\/terms\/","foaf":"http:\/\/xmlns.com\/foaf\/0.1\/","og":"http:\/\/ogp.me\/ns#","rdfs":"http:\/\/www.w3.org\/2000\/01\/rdf-schema#","sioc":"http:\/\/rdfs.org\/sioc\/ns#","sioct":"http:\/\/rdfs.org\/sioc\/types#","skos":"http:\/\/www.w3.org\/2004\/02\/skos\/core#","xsd":"http:\/\/www.w3.org\/2001\/XMLSchema#","owl":"http:\/\/www.w3.org\/2002\/07\/owl#","rdf":"http:\/\/www.w3.org\/1999\/02\/22-rdf-syntax-ns#","rss":"http:\/\/purl.org\/rss\/1.0\/","site":"https:\/\/www.bco-dmo.org\/ns#","odo":"http:\/\/ocean-data.org\/schema\/","emo":"http:\/\/ocean-data.org\/schema\/entity-matching#","bibo":"http:\/\/purl.org\/ontology\/bibo\/","crypto":"http:\/\/id.loc.gov\/vocabulary\/preservation\/cryptographicHashFunctions\/","bcodmo":"http:\/\/lod.bco-dmo.org\/id\/","tw":"http:\/\/tw.rpi.edu\/schema\/","dcat":"http:\/\/www.w3.org\/ns\/dcat#","time":"http:\/\/www.w3.org\/2006\/time#","geo":"http:\/\/www.w3.org\/2003\/01\/geo\/wgs84_pos#","geosparql":"http:\/\/www.opengis.net\/ont\/geosparql#","sf":"http:\/\/www.opengis.net\/ont\/sf#","void":"http:\/\/rdfs.org\/ns\/void#","sd":"http:\/\/www.w3.org\/ns\/sparql-service-description#","dctype":"http:\/\/purl.org\/dc\/dcmitype\/","prov":"http:\/\/www.w3.org\/ns\/prov#","schema":"http:\/\/schema.org\/","geolink":"http:\/\/schema.geolink.org\/1.0\/base\/main#","spdx":"http:\/\/spdx.org\/rdf\/terms#","bcodmo_vocab":"http:\/\/schema.bco-dmo.org\/"},"@id":"http:\/\/lod.bco-dmo.org\/id\/dataset\/652668#graph","@graph":[{"http:\/\/lod.bco-dmo.org\/id\/dataset\/652668":{"@id":"http:\/\/lod.bco-dmo.org\/id\/dataset\/652668","@type":["http:\/\/ocean-data.org\/schema\/DeploymentDatasetCollection","http:\/\/www.w3.org\/ns\/dcat#Dataset","http:\/\/ocean-data.org\/schema\/Dataset"],"http:\/\/ocean-data.org\/schema\/hasAcquisitionDescription":[{"@value":"
Wozniak et al. (2014) and Gurganus et al. (2015) detail the sampling and analytical methodology for these data. The full citations are listed below. Details for the aerosol sampling can also be found in Wozniak et al. (2013).<\/p>\n
The analytical details from Wozniak et al. (2014) are as follows:
\nAerosol WSOM (10 mL) was solid-phase extracted using a styrene divinyl benzene polymer (PPL, Varian) cartridges following published procedures (e.g., Dittmar et al., 2008; Mitra et al., 2013). The PPL cartridge was rinsed with two cartridge volumes of LC\u2013MS grade methanol and acidified Milli-Q water before the pre-filtered and acidified aerosol WSOM was loaded onto the cartridge. The relatively hydrophobic dissolved OM (DOM) is retained on the PPL cartridge while highly hydrophilic WSOM and salts (which would otherwise compete with the aerosol WSOM for charge during ESI) pass through the cartridge. The cartridge was then rinsed with 0.01 M HCl to ensure complete removal of salts, dried under a stream of ultrapure nitrogen, and eluted with one cartridge volume (~3 mL) of methanol. Though previous studies have added ammonium hydroxide prior to ESI in order to increase ionization, tests showed that higher quality spectra (more organic matter peaks) were obtained without the addition of base, and samples were infused to the ESI in methanol alone. Samples were continuously infused into an Apollo II ESI ion source of a Bruker Daltonics 12 T Apex Qe FTICR, housed at ODU\u2019s COSMIC facility. Samples were introduced by a syringe pump at 120 uL h-1. All samples were analyzed in negative ion mode; ions were accumulated in a hexapole for 0.5 s before being transferred to the ICR cell, where 300 transients were co-added. The summed free induction decay signal was zero-filled once and sinebell apodized prior to fast Fourier transformation and magnitude calculation using the Bruker Daltonics Data Analysis software.<\/p><\/div>","@type":"rdf:HTML"}],"http:\/\/ocean-data.org\/schema\/hasBriefDescription":[{"@value":"m\/z and peak intensity data for the molecular formulas assigned to each aerosol water soluble organic matter sample run by ESI FTICR MS.","@language":"en-US"}],"http:\/\/purl.org\/dc\/terms\/description":[{"@value":"
The sampling details and identities are provided for\u00a0each of the sample along with the FTICR MS (Fourier transform ion cyclotron resonance mass spectrometry) data for each sample. This includes: the starting and ending locations (latitudes and longitudes) and times (Greenwich mean time) as well as the sampling rates (m3 min-1) and calculated sample volumes (m3) for each of the aerosol samples. The run times (measured in hours) and sample volumes account for periods when the sampler was stopped due to potential contamination from the ship\u2019s stack. The FTICR MS data include:\u00a0molecular formulas assigned to peaks at various m\/z in Fourier Transform ion cyclotron resonance mass spectra. The formulas consist of carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus. The \u2018m\/z\u2019 and \u2018intensity\u2019 columns are generated by the Bruker software, and the molecular formula and exact mass data are generated by the investigators'\u00a0molecular formula assignment protocol described in the next section.<\/p><\/div>","@type":"rdf:HTML"}],"http:\/\/www.w3.org\/2000\/01\/rdf-schema#label":[{"@value":"GT10-11 - Aerosol FTICR MS","@type":"xsd:string"}],"http:\/\/ocean-data.org\/schema\/hasProcessingDescription":[{"@value":"
The data were processed as described in Wozniak et al. (2014):
\nAll mass spectra were externally calibrated with a polyethylene glycol standard and internally calibrated with naturally occurring fatty acids and other homologous series present within the sample (Sleighter and Hatcher, 2008). A molecular formula calculator (Molecular Formula Calc v. 1.0 \u00a9NHMFL, 1998) generated molecular formulas using carbon (12C8\u201350), hydrogen (1H8\u2013100), oxygen (16O1\u201330), nitrogen (14N0\u20135), sulfur (32S0\u20132), and phosphorous (31P0\u20132). Peaks identified in process blanks (PPL extract of QMA filter blank WSOM) were subtracted from the sample peak list prior to formula assignment. Only m\/z values in the range of 200-800 with a signal to noise ratio above 3 were used for molecular formula assignments. The mean mass resolution for all samples over that mass range was 560,000.<\/p>\n
Constraints corresponding to the standard range of atomic composition for natural organic matter were applied during formula assignment following previous work (Stubbins et al., 2010; Wozniak et al., 2008): (1) O\/C \u2264 1.2; (2) 0.3 \u2264 H\/C \u2264 2.25; (3) N\/C \u2264 0.5; (4) S\/C \u2264 0.2; (5) P\/C \u2264 0.2; (6) DBE \u2265 0 and an integer value. The term DBE is the number of double bond equivalents, which is the number of double bonds and rings in a formula (e.g., Hockaday et al., 2006). The measured m\/z values and assigned formula calculated exact masses all agreed within the maximum allowed error of 1.0 ppm, and >90% of formulas were within 0.5 ppm. An unequivocal formula is found for m\/z values below 450, but above this, multiple formulas may match the measured m\/z value. In order to ensure a unique formula per peak, additional constraints are placed on the proportion of heteroatoms using the following criteria (Kujawinski et al., 2009): 1) each formula should have numbers of N and S atoms that are each fewer than the number of oxygen atoms, and 2) the sum of the N and S atoms should be the lowest possible.<\/p>\n
The spectral magnitude for a given peak results from a combination of the concentrations of the isomeric compounds representing a given molecular formula in the actual WSOM, how ionizable those compounds are using ESI, and the FTICR MS analytical window. ESI FTICR MS is thus not a purely quantitative technique.<\/p>\n
References:<\/strong> Hockaday, W., Grannas, A., Kim, S., and Hatcher, P. 2006.\u00a0Direct molecular evidence for the degradation and mobility of black carbon in soils from ultrahigh-resolution mass spectral analysis of dissolved organic matter from a fire-impacted forest soil.\u00a0Org. Geochem., 37, 501-510. doi:10.1016\/j.orggeochem.2005.11.003<\/a><\/p>\n Kujawinski, E. B., Longnecker, K., Blough, N. V., Vecchio, R. D., Finlay, L., Kitner, J. B., and Giovannoni, S. J. 2009.\u00a0Identification of possible source markers in marine dissolved organic matter using ultrahigh resolution mass spectrometry.\u00a0Geochim. Cosmochim. Acta, 73, 4384-4399. doi:10.1016\/j.gca.2009.04.033<\/a><\/p>\n Mitra, S., Wozniak, A. S., Miller, R., Hatcher, P. G., Buonassissi, C., and Brown, M. 2013.\u00a0Multiproxy probing of rainwater dissolved organic matter (DOM) composition in coastal storms as a function of trajectory.\u00a0Mar. Chem., 154, 67-76. doi:10.1016\/j.marchem.2013.05.013<\/a><\/p>\n Sleighter, R. L. and Hatcher, P. G. 2008. Molecular characterization of dissolved organic matter (DOM) along a river to ocean transect of the lower Chesapeake Bay by ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.\u00a0Mar. Chem., 110, 140-152. doi:10.1016\/j.marchem.2008.04.008<\/a><\/p>\n Stubbins, A., Spencer, R. G., Chen, H., Hatcher, P. G., Mopper, K., Hernes, P. J., Mwamba, V. L., Mangangu, A. M., Wabakanghanzi, J. N., and Six, J. 2010.\u00a0Illuminated darkness: Molecular signatures of Congo River dissolved organic matter and its photochemical alteration as revealed by ultrahigh precision mass spectrometry.\u00a0Limnol. Oceanogr., 55, 1467-1477. doi:10.4319\/lo.2010.55.4.1467<\/a><\/p>\n Wozniak, A.S., Bauer, J.E., Sleighter, R.L., Dickhut, R.M., Hatcher, P.G.\u00a02008. Technical Note: Molecular characterization of aerosol-derived water soluble organic carbon using ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.\u00a0Atmos. Chem. Phys., 8, 5099-5111. doi:10.5194\/acp-8-5099-2008<\/a><\/p>\n Wozniak, A. S., R. L. Sleighter, H. Abdulla, A. S. Priest, P. L. Morton, R. U. Shelley, W. M. Landing, and P. G. Hatcher. 2013. Relationships among aerosol water soluble organic matter, iron and aluminum in European, North African, and Marine air masses from the 2010 US GEOTRACES cruise. Marine Chemistry, 154, 24-33. doi:10.1016\/j.marchem.2013.04.011<\/a><\/p>\n
\nGurganus, S. C., A. S. Wozniak, and P. G. Hatcher. 2015. Molecular characteristics of the water soluble organic matter in size resolved aerosols collected over the North Atlantic Ocean. Marine Chemistry, 170, 37-48,\u00a0doi:10.1016\/j.marchem.2015.01.007<\/a><\/p>\n