02185naa a2200205 a 450000100080000000500110000800800410001910000220006024500970008226000090017950000290018852014040021765300300162165300210165165300260167270000240169870000170172270000200173977302200175910285692007-09-11       2004    bl ---       0--  u    #d1 aBARRIQUELLO M. F.  aFluorescence spectroscopy comparison of soil humic acids and model humic acid-type polymers.  c2004  aCLASSIFICAÇÃO CDD: 630  aI. INTRODUCTION  Humic Substances (HS) have been object of numerous studies, but the basic che and lhe reactivity 01 them are still not well understood. A consensus exists that lhe Iraction of soil organic matter receives an important contribution from polymerizatio involving both phenolic compounds and thedegradation products of proteinaceous mate et al.,1990, Zech et al., 1997). Recognition of this pathway to humus formation has  number of investigations in which humic acid-type polymers have been synthesized and th properties compared to those of natural humic acid These studies have been useful to the identification of significant processes leading to humification and to lhe elucidation of molecular structure of soil organic matter. Fluorescence spectroscopy has been recentl powerful means for the evaluation of humification and molecular size of  humic substan et al., 1999; Kalbitz et. al., 1999, Milori et al., 2002). Although lhe fluorescent structures substances depends on their properties of several molecular and environment paramete molecular weight, concentration and pH, render their investigation particularly useful to obtain unique information, not only about lhe fluorescence behavior but algo about lhe general nature a of humic materiais (Senesi et al., 1991). In this work, lhe fluorescence spectra of lhe mo are studied in comparison with the spectra of natural HA.  afluorescence spectroscopy  aSoil humic acids  asynthetic humic acids1 aMILORI, D. M. B. P.1 aNEVES, E. A.1 aMARTIN-NETO, L.  tIn: MARTIN-NETO, L.; MILORI, D.M.B.P.; SILVA, W.T.L. (Ed.). Humic substances and soil and water environment: International Meeting of IHSS, 12. São Carlos : Embrapa Instrumentação Agropecuária, 2004. p. 358-360.