The analytical and data processing methodology have been described in Wozniak et al. (2013, 2015). The full citations for these references are listed below. A summary of the methods is quoted here:

Aerosol total organic carbon (TOC = organic carbon + elemental carbon) concentrations were measured using a CE Elantech Flash EA 1112 series elemental analyzer following published protocols (e.g., Wozniak et al., 2008; 2011). Briefly, aerosol subsamples (2.84 cm2) were taken from the QMA filter samples with a stainless steel cork borer plug, acidified with 1M HCl to remove inorganic carbonates, and dried overnight at 60 degrees C. Triplicate acidified filter plugs were placed in 5x9 mm tin cups and combusted at 900 degrees C in the presence of O2. Sample response areas were calibrated to a standard curve generated with an aspartic acid standard. Mean filter blank TOC (~0.0035 ± 0.0006 mg C per plug) amounts were subtracted to calculate TOC values.

Aerosol WSOC concentrations were measured on a Shimadzu TOC-V Combustion Analyzer using high temperature (680 degrees C) Pt-catalyzed oxidation coupled to non-dispersive infrared gas detection of CO2 following published procedures (Wozniak et al., 2008; 2012). Calibration curves for WSOC were created using a potassium hydrogen phthalate standard. All samples for WSOC analysis were acidified to remove inorganic carbon with 2-3 drops of 1M hydrochloric acid constituted in ultrapure water and analyzed in triplicate. Samples were blank corrected by subtracting mean contributions from filter blank material extracted in ultrapure water.

References:
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., Bauer, J.E., Dickhut, R.M. 2011. Fossil and contemporary aerosol particulate organic carbon in the eastern United States: Implications for deposition and inputs to watersheds. Global Biogeochem. Cycles, 25, GB2013. doi:10.1029/2010GB003855

Wozniak, A.S., Bauer, J.E., Dickhut, R.M. 2012. Characteristics of water-soluble organic carbon associated with aerosol particles in the Eastern United States. Atmos. Environ., 46, 181-188. doi:10.1016/j.atmosenv.2011.10.001

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., R. U. Shelley, S. M. McElhenie, A. S. Willoughby, W. M. Landing, P. G. Hatcher. 2015. Insights into potential Fe-binding aerosol water soluble organic ligands from the 2011 US GEOTRACES cruise. Marine Chemistry, 173, 162-172, doi:10.1016/j.marchem.2014.11.002

GT10-11_Aerosol_C.csv