Study of a Model Humic Acid-type Polymer by Fluorescence Spectroscopy and Atomic Force Microscopy

Marcilene Ferrari Barriquello, Fábio de Lima Leite, Daiana Kotra Deda, Sérgio da Costa Saab, Nelson Consolin-Filho, Marcos Antonio Piza, Ladislau Martin-Neto

Embrapa Instrumenta??o Agropecuária, CP 741, 13560-970, S?o Carlos, SP, Brazil.
Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR, Brazil.
Universidade Federal de S?o Carlos, CP 3031, 18052-780, Sorocaba, SP, Brazil.
Universidade Federal de Sao Carlos, CP 3031, 18052-780, Sorocaba, SP, Brazil.
Universidade Tecnológica Federal do Paraná, 87301-006, Campo Mour?o, PR, Brazil.
Universidade Tecnológica Federal do Paraná, 87301-006, Campo Mourao, PR, Brazil.

DOI: 10.4236/msa.2012.37067                

Abstract

A model HA-type polymer of para-benzoquinone synthetic humic acid (SHA) and its complexes with copper, iron and manganese metal ions were studied using atomic force microscopy (AFM). Natural humic acids (HA) and synthetic humic acids (SHA) were examined by fluorescence spectroscopy, which indicated similarity of SHA and HA spectra. The AFM images of SHA and its complexes revealed variable morphologies, such as small spheres, aggregates and a sponge-like structure. The SHA complexes displayed morphologies similar to those of natural HA. The presence of copper, iron and manganese ions led to the formation of aggregate-type structures in an apparent arrangement of smaller SHA particles.

Keywords

Humic Substances; Synthetic Humic Acids; Metal Complexes; AFM; Fluorescence Spectroscopy

Conflicts of Interest

The authors declare no conflicts of interest.

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