Chemical and biological studies on environmental humic acids II.¹H-nmr and IR spectra of humic acids

Spectroscopic and structural characterization of a fulvic acid from weathered coal

“…Figure 3a and 3b, Figure 4a and 4b). For example, it is generally thought that amide I and II bands can not be observed in IR spectra of humic substances with high degree of humification 17 The results here show that FT-IR spectra with good quality are sensitive enough to characterize some fine compositional and structural information. One of the most important reasons why the FT-IR spectra with lower neutralization degree are higher resolved results from very weak H-bonding interaction among molecules 18 .…”

Characteristics of humic substances and dynamics of dissolved organic matter in forest soils in northern Kyoto with special reference to their pedogenetic processes

“…Chemical shifts were measured in relation to the internal TMS. Each peak was interpreted based on the studies carried out by Wilson (1981), Wershaw (1985), and Yonebayashi and Hattori (1989). Remarkable characteristics of the fulvic and humic acids are summarized as follows:…”

Chemical alterations of tropical peat soils determined by Waksman's proximate analysis and properties of humic acids

“…The former humic acids were considered to have long aliphatic chains based on the assumption that they had poorly branched aliphatic chains. In our previous paper (Yonebayashi and Hattori 1989), we reported that sediment humic acids had long aliphatic chains. Hatcher et al (1983) suggested that some marine peats contain humic substances with mainly aliphatic carbon atoms, as a result of NMR studies, presumably because the sediment was derived from marine algae.…”

“…lH-NMR spectra and IR spectra of humic acids were obtained from DMSOd 6 solution and KBr discs, respectively, as described in a previous paper (Yonebayashi and Hattori 1989).…”