Thermogravimetry of soil humic compounds

Sedimentary humic substances in the northern Adriatic sea (Mediterranean sea)

“…Between 380 and 500°C the dissociation and breakdown of polyunsaturated structures and the elimination of hydrogen through the cracking of heterocyclic oxygen groups occurs. Above 500°C, up to 800°C, all the alicyclic carbon structures disappear (Ioselis et al, 1985;Juntgen, 1984;Schnitzer & Hoffman, 1965;Sheppard & Forgeron, 1987). The HA examined displayed a non negligible fraction that decomposed at temperatures below 350°C, suggesting a high content in functional groups and in aliphatic structures, which is in accordance with the FTIR and 13 C NMR spectra.…”

Application of thermal analysis techniques in soil science

“…During the 1960s, Turner and Schnitzer (1962), Schnitzer et al (1964) and Schnitzer and Hoffman (1965) pioneered the use of TG, in combination with other techniques such as infrared spectroscopy and elemental analysis, for studying podzolic soil humic substances. They detected two exothermic peaks between 200 and 500°C for all samples.…”

Effects of charring on mass, organic carbon, and stable carbon isotope composition of wood

“…Increasing mass loss with temperature is typical for isothermal charring and analytical pyrolysis (Schnitzer and Hoffman, 1965;Drysdale, 1999;Schleser et al, 1999;Sharma et al, 2001). Mackay and Roberts (1982) found a higher char yield from wood charring (30%) which may be explained by trapping of tar (e.g.…”