Dataset: GT10-11 - Aerosol FTICR MS
Deployment: KN204-01

m/z and peak intensity data for the molecular formulas assigned to each aerosol water soluble organic matter sample run by ESI FTICR MS.

Principal Investigator:

Andrew S. Wozniak (Old Dominion University, ODU)

Co-Principal Investigator:

Patrick G. Hatcher (Old Dominion University, ODU)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Role of Organic Matter in Determining the Solubility of Atmospherically-Delivered Iron (GEOTRACES Aerosol OM)

U.S. GEOTRACES North Atlantic Transect (GA03) (U.S. GEOTRACES NAT)

Current State:

Final no updates expected

Version:

29 Dec 2015

Deployment Synonyms:

GA03, GT11, KN204-01A, KN204-01B, USGT-NAT-2011, USGNAZT, GNAT, 316N20111106, KN204-1

Version Date:

2015-12-29

Data URL:

https://www.bco-dmo.org/dataset-deployment/652673/data

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Description

The sampling details and identities are provided for each 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’s stack. The FTICR MS data include: molecular 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 ‘m/z’ and ‘intensity’ columns are generated by the Bruker software, and the molecular formula and exact mass data are generated by the investigators' molecular formula assignment protocol described in the next section.

Methods & Sampling

Dataset acquisition description

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).

The analytical details from Wozniak et al. (2014) are as follows:
Aerosol 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–MS 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’s 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.

Data Processing Description

Dataset Processing Description

The data were processed as described in Wozniak et al. (2014):
All 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 ©NHMFL, 1998) generated molecular formulas using carbon (12C8–50), hydrogen (1H8–100), oxygen (16O1–30), nitrogen (14N0–5), sulfur (32S0–2), and phosphorous (31P0–2). 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.

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 ≤ 1.2; (2) 0.3 ≤ H/C ≤ 2.25; (3) N/C ≤ 0.5; (4) S/C ≤ 0.2; (5) P/C ≤ 0.2; (6) DBE ≥ 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.

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.

References:
Gurganus, 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, doi:10.1016/j.marchem.2015.01.007

Hockaday, W., Grannas, A., Kim, S., and Hatcher, P. 2006. Direct 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. Org. Geochem., 37, 501-510. doi:10.1016/j.orggeochem.2005.11.003

Kujawinski, E. B., Longnecker, K., Blough, N. V., Vecchio, R. D., Finlay, L., Kitner, J. B., and Giovannoni, S. J. 2009. Identification of possible source markers in marine dissolved organic matter using ultrahigh resolution mass spectrometry. Geochim. Cosmochim. Acta, 73, 4384-4399. doi:10.1016/j.gca.2009.04.033

Mitra, S., Wozniak, A. S., Miller, R., Hatcher, P. G., Buonassissi, C., and Brown, M. 2013. Multiproxy probing of rainwater dissolved organic matter (DOM) composition in coastal storms as a function of trajectory. Mar. Chem., 154, 67-76. doi:10.1016/j.marchem.2013.05.013

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. Mar. Chem., 110, 140-152. doi:10.1016/j.marchem.2008.04.008

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. Illuminated darkness: Molecular signatures of Congo River dissolved organic matter and its photochemical alteration as revealed by ultrahigh precision mass spectrometry. Limnol. Oceanogr., 55, 1467-1477. doi:10.4319/lo.2010.55.4.1467

Wozniak, A.S., Bauer, J.E., Sleighter, R.L., Dickhut, R.M., Hatcher, P.G. 2008. Technical Note: Molecular characterization of aerosol-derived water soluble organic carbon using ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Atmos. Chem. Phys., 8, 5099-5111. doi:10.5194/acp-8-5099-2008

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

Wozniak, A.S., A. S. Willoughby, S. C. Gurganus, P. G. Hatcher. 2014. Distinguishing molecular characteristics of aerosol water soluble organic matter from the 2011 trans-North Atlantic US GEOTRACES cruise. Atmospheric Chemistry and Physics, 14, 8419-8434, doi:10.5194/acp-14-8419-2014

BCO-DMO Processing:
- Modified parameter names to conform with BCO-DMO naming conventions;
- merged FTICR data with sample information;
- added cruise id, event numbers, and station numbers from BCO-DMO GEOTRACES NAT master event file;
- replaced missing data with 'nd';
- converted date-time fields to ISO format;
- changed longitude values to negative.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1234166	NSF Division of Ocean Sciences

Instruments

Aerosol Sampler

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: Aerosol Sampler

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/13/

Generic Description:

A device that collects a sample of aerosol (dry particles or liquid droplets) from the atmosphere.

Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

Supplied Name: Bruker Daltonics 12 T Apex Qe FTICR

Supplied Description:

Samples were continuously infused into an Apollo II ESI ion source of a Bruker Daltonics 12 T Apex Qe FTICR, housed at ODU's COSMIC facility.

Instrument Type

Generic Name: Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

Acronym: FTICR MS

Generic Description:

In Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, the mass-to-charge ratio (m/z) of an ion is experimentally determined by measuring the frequency at which the ion processes in a magnetic field. These frequencies, which are typically in the 100 KHz to MHz regime, can be measured with modern electronics making it possible to determine the mass of an ion to within +/- 0.000005 amu or 5 ppm.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise_id	Cruise identifer	unitless	cruise_id
sample_GEOTRC	GEOTRACES sample number	unitless	sample
event_GEOTRC	GEOTRACES event number; added from the BCO-DMO GEOTRACES NAT master events file.	unitless	event
station	Station number; added from the BCO-DMO GEOTRACES NAT master events file.	unitless	sta
filter_size	Filter size. Whatman QMA filters are typically sold as 8"x10" sheets in the U.S.	inches	filter_size
filter_type	Filter type	unitless	no_bcodmo_term
ISO_DateTime_UTC_Start	Date and time, formatted to ISO8601 standard, at the start of the sampling event. Format: YYYY-mm-ddTHH:MM:SS.xx	unitless	ISO_DateTime_UTC
lat_start	Latitude at the start of the sampling event.	decimal degrees	lat_start
lon_start	Longitude at the start of the sampling event.	decimal degrees	lon_start
ISO_DateTime_UTC_End	Date and time, formatted to ISO8601 standard, at the end of the sampling event. Format: YYYY-mm-ddTHH:MM:SS.xx	unitless	ISO_DateTime_UTC
lat_end	Latitude at the end of the sampling event.	decimal degrees	lat_end
lon_end	Longitude at the end of the sampling event.	decimal degrees	lon_end
run_time	Run time in hours	hours	no_bcodmo_term
flow_rate	Sampling rate	cubic meters per minute (m3 min-1)	no_bcodmo_term
total	Total sample size	cubic meters (m3)	no_bcodmo_term
m_to_z	The measured m/z of the peak of interest. (The m refers to the molecular or atomic mass number and z to the charge number of the ion.)	dimensionless	no_bcodmo_term
intensity	Peak intensity; represents a measure of the relative response for each given peak.	?	no_bcodmo_term
C	The number of each element, C, in the assigned molecular formula of the detected singly, negatively, charged ion.	unitless	no_bcodmo_term
H	The number of each element, H, in the assigned molecular formula of the detected singly, negatively, charged ion.	unitless	no_bcodmo_term
H_1	H+1. Give the number of H in the neutral molecule.	unitless	no_bcodmo_term
N	The number of each element, N, in the assigned molecular formula of the detected singly, negatively, charged ion.	unitless	no_bcodmo_term
O	The number of each element, O, in the assigned molecular formula of the detected singly, negatively, charged ion.	unitless	no_bcodmo_term
S	The number of each element, S, in the assigned molecular formula of the detected singly, negatively, charged ion.	unitless	no_bcodmo_term
P	The number of each element, P, in the assigned molecular formula of the detected singly, negatively, charged ion.	unitless	no_bcodmo_term
exact_mass	The mass of the assigned molecular formula.	?	no_bcodmo_term

Database

Contribute Data

Dataset: GT10-11 - Aerosol FTICR MS
Deployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GT10-11 - Aerosol FTICR MSDeployment: KN204-01

Dataset acquisition description

Dataset Processing Description

Dataset: GT10-11 - Aerosol FTICR MS
Deployment: KN204-01