EPR, FTIR, Raman, UV–Visible Absorption, and Fluorescence Spectroscopies in Studies of NOM

Effect of no-tillage and amendments on carbon lability in tropical soils

“…The increase of the humification degree of SOM and the decrease of Clight fraction as a function of increasing amounts of sludge may be due to the improvement of the microbial activity in the soil. This microbial activity was caused by an excessive incorporation of nutrients, stimulating microorganisms to consume the labile organic material in the soil, such that only the most recalcitrant material remains (priming effect) (Heimann and Reichstein, 2008;Martin-Neto et al, 2009).…”

“…In the case of gypsum amendment, an improvement of the humification degree occurred in the samples after the second application and almost no variation in the single application. The decrease of Humification Index in general represents the incorporation of fresh organic matter into the soil with increase of the SOM content (Martin-Neto et al, 2009). Based on this argumentation, the humification indices obtained by fluorescence were coherent with total organic carbon described in Table 1.…”

“…The Milori method agrees with the I Arom/Alip and occluded fraction as well, showing strong correlation with aromatic moieties. The humification indices obtained with the methods of Kalbitz et al (1999) and Zsolnay et al (1999) and via LIF are inversely proportional to the carbon content of the samples; as carbon content increases, the degree of humification of the sample decreases, indicating that fresh organic matter had been incorporated into the soils, mainly in the light fraction, which is considered the most sensible to tillage soil changes (Martin-Neto et al, 2009).…”

Solid Phases Precipitating in Artificial Urine in the Absence and Presence of Bacteria Proteus mirabilis—A Contribution to the Understanding of Infectious Urinary Stone Formation

“…Unfortunately, in spite of the use of a Fourier-Transform Raman system with the IR excitation source (Nd:YAG laser, λ = 1064 nm), the re-emission (fluorescence) overlapped the Raman signal. This is a phenomenon quite often observed for biological material (microorganisms or the products of their activity) [26,27].…”

Estudo da matéria orgânica e composição elementar de solos arenosos de regiões próximas a São Gabriel da Cachoeira no Amazonas

“…A espectroscopia de FIL tem como princípio básico excitar a amostra de solo com um laser com emissão na região do azul ou violeta o que resulta na fluorescência de grupos funcionais mais complexos da MOS, tais como estruturas aromáticas e heterocíclicas Martin-Neto et al, 2009 .…”