Copper(II) titration of fulvic acid ligand sites with theoretical, potentiometric, and spectrophotometric analysis

Dicarboxylic acids, ketocarboxylic acids and glyoxal in the marine aerosols collected during a round-the-world cruise

“…Specifically, there is growing evidence that oxalic acid, one of the most abundant organic species in the atmosphere, is a product of cloud processing (Sorooshian et al, 2006). Furthermore, dicarboxylic acids can form strong organic complexes with metals (Gamble et al, 1980;Santana-Casiano et al, 2000). Thus, the atmospheric transport, marine primary emission, as well as in situ formation of dicarboxylic acids in the atmosphere may influence the biogeochemical cycles of heavy metals (e.g., Fe and Hg).…”

Study of the pH influence on the optical properties of dissolved organic matter using fluorescence excitation–emission matrix and parallel factor analysis

“…Early studies used single excitation and emission wavelengths, which are typical of humic-like fluorophores [8,[10][11][12][13][14][15][16]. Fluorescence excitation-emission matrix (EEM) spectroscopy can measure emission spectra across a range of excitation wavelengths and provide an overall view of all the features that exist within a selected spectral range.…”

Ionization constants of a soil fulvic acid

“…Gamble [4] proposed a model that assumes the existence of a continuous distribution of different functional groups. K varies continuously and the frequency distributions can be integrated over that variable.…”

“…Reported potentiometric studies on humic substances suggest that their deprotonation reflects a polyelectrolyte nature and functional group heterogeneity. This has led to the development of various methods for interpreting the acid-base equilibria of humic substances in the framework of two major types of modelling, namely the discrete ligand approach [2,3] and the continuous distribution approach [4].…”