Bubble Bursting experiments during PI-ICE project: H-NMR spectra statistical analyses

Main statistical analysis results on H-NMR spectra of "Quality over quantity: organic compounds altering the Antarctic Sea spray aerosol concentrations" by Manuel Dall’Osto et al. Work-sheets: Data_62x401 reporting the elaborated H-NMR spectra of all the POC and SSA samples collected from all the bubble bursting experiments during PI-ICE and used as INPUT matrix for the subsequent multivariate statistical analyses (see the related paper for details) the original spectra are aligned all together and truncated to remove the interferent signals from solvent (H2O signal around 4.9ppm), of the buffer (around 8.45ppm) and the extremes (>9 and < 0.5ppm); then they are binned every 40 points (corresponding to 0.02ppm) before the statistical analysis in order to have about 400 final chemical shifts Err_62x401 reporting the "Error matrix" necessary for the Positive Matrix Factorization (PMF) application and representing the uncertainties associated to each data point of the spectra in the INPUT matrix (Data_62x401) Uncertainty/error matrix is calculated from the signal-to-noise ratios of the NMR spectra, as already described in previous publications cited in the paper (Decesari et al., 2011; Finessi et al., 2012; Paglione et al., 2014a) POC+SSA PCA reporting the spectral loadings and scores of the Principl Components (PCs) resulting from the PCA analysis of H-NMR POC and SSA dataset. POC nn-fa reporting the spectral profiles and contributions of the factors resulting from the nonnegative factor analyses of H-NMR POC dataset. in particular are reported 2 different solutions from the two different algorithm used -ME2, appling the Multilinerar-engine method by Paatero et al. (1999) -MCR, i.e., applying the Multi Curve Resolution - Alternating Least Square algorithm by Jaumot et al. (2005) and Tauler (1995) and the mean values between the two Contributions are expressed as relative contributions of each factor to the total WSOC concentrations measured by H-NMR (which in turn are reported in the specific column AK named "WSOC by NMR_tot" as 𝜇molH in the extract ) SSA nn-fa reporting the spectral profiles and contributions of the factors resulting from the nonnegative factor analyses of H-NMR Sea-Spray Aerosol (SSA) dataset. in particular are reported 2 different solutions from the two different algorithm used -ME2, appling the Multilinerar-engine method by Paatero et al. (1999) -MCR, i.e., applying the Multi Curve Resolution - Alternating Least Square algorithm by Jaumot et al. (2005) and Tauler (1995) and the mean values between the two Contributions are expressed as relative contributions of each factor to the total WSOC concentrations measured by H-NMR (which in turn are reported in the specific column S named "WSOC by NMR_tot", expressed in 𝜇molH m-3)