This dataset and the methods used to obtain it are described in Chapter 3 of "EXTREME MOLECULAR DIVERSITY IN BIOMASS BURNING ATMOSPHERIC ORGANIC AEROSOL OBSERVED THROUGH ULTRAHIGH RESOLUTION MASS SPECTROMETRY" a Dissertation prepared by Matthew Brege and submitted as a Doctoral Thesis. This work can be accessed here: https://doi.org/10.37099/mtu.dc.etdr/927
Briefly, four days worth of concurrent daytime/nighttime aerosol and fog water samples were collected at San Pietro Capofiume in the Emilia Romagna region of Italy from 1-Dec to 4-Dec, 2015. The water soluble extracts of the aerosol filters and aliquots of the fog water were analyzed using ultrahigh resolution Orbitrap mass spectrometry (OTE-MS) using positive and negative modes of electrospray ionization. Data was collected for 100-200 scans over the range of m/z 100 to 800 and at a resolution of 240,000 (defined at m/z 400) with spectrum averaging. Mass lists were generated from an average of the scans using Xcalibur software (Thermo Scientific v. 3.0). The newly developed MFAssignR (Schum et al. 2020) was used to estimate the noise threshold, recalibrate the spectra and assign molecular formulas to the measured masses. A series of custom R scripts (R v. 3.5.1 and RStudio v. 1.1.463) were used to perform blank subtraction and authenticate data quality. The resulting molecular formula assignments were reviewed for their credibility with respect to: oxygen to carbon ratio (O/C), hydrogen to carbon ratio (H/C), double bond equivalents (DBE), and absolute PPM mass error. The assigned molecular formulas were also analyzed using DBE and oxygen number trends as described by Herzsprung et al. (2014) and the unreliable formula assignments were removed.
Schum, S. K.; Brown, L. E.; Mazzoleni, L. R., MFAssignR: Molecular formula assignment software for ultrahigh resolution mass spectrometry analysis of environmental complex mixtures. Environmental Research 2020, 191, 110114.
Herzsprung, P., Hertkorn, N., von Tumpling, W., Harir, M., Friese, K., and Schmitt-Kopplin, P.: Understanding molecular formula assignment of Fourier transform ion cyclotron resonance mass spectrometry data of natural organic matter from a chemical point of view, Anal Bioanal Chem, 406, 7977-7987, 2014.
Brege, M.A. and Mazzoleni, L.R. Ultrahigh resolution OTE-MS data for wildfire-influenced tar ball aerosol from Ultrahigh resolution OTE-MS data for ambient daytime and nighttime aerosol and ambient fog water from San Pietro Capofiume, 2021.