Fulvic acids thermal analysis

Applications of NMR, ESR, thermal analysis, spectrophotometry, gas chromatography, and GC-MS to humic and fulvic acid analysis have been reviewed by Schnitzer [452]. 

Thermal analysis of humic-mineral complexes has shown there is an overall reduction in the decomposition temperatures of humic acid that has been com-plexed to a mineral surface. Changes in the exothermic peak temperatures of humic substances in the free and complexed state are well-documented for synthetic mineral complexes with humic and fulvic acid (Schnitzer and Kodama, 1972 Tan, 1977 Schnitzer and Ghosh, 1982) as well as for authentic soil complexes. 

Schnitzer, M., and Kodama, H. (1972). Differential thermal analysis of metal-fulvic acid salts and complexes. Geoderma 7, 93-103. 

Figure 18.25. Thermal mechanical analysis scans of Nordic aquatic fulvic acid (NAFA) and Nordic aquatic humic acid (NAHA) indicating transitions near 18 °C and 23 °C, respectively, associated with the collapse of the structures following thermal transitions. Reproduced from DeLapp and LeBoeuf (2004), by permission of the Soil Science Society of America.

Jambu, R, Dupuis,T., and Garais, M. (1975a). Use of differential thermal-analysis to characterize fulvic acid metal complexes and humic acid metal complexes. 2. Application to natural organometallic complexes. J. Therm. Anal. 8(2), 231-237. 

Kodama, H. and Schnitzer, M. (1968). Thermal analysis of a fulvic acid-montmorillonite com-... 

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