Physicochemical and Spectroscopic Characterization of Humic and Fulvic Acids Isolated from South-Bohemian Peat

abstrakt

angličtina

The aim of this work was study chemical composition and structure of different HS. Object of our study were two samples HS which were isolated from South-Bohemian peat from the quarry Branná near Třeboň, Czech Republic. Isolation of HS was performed according to the procedure recommended by the IHSS. All samples of HS were characterized by elemental analysis (EA), ultraviolet-visible spectroscopy (UV/Vis), infrared spectroscopy (FTIR) and steady-state fluorescence spectroscopy. Absorption coefficients (EET/EBz, E250/E365 and E465/E665) of HS were calculated from the absorbance values. Infrared spectroscopy is a useful technique in characterization of structure, functional groups and formation modes of HS. For the fluorescence experiments the final concentration of the HS was adjusted to 10 mg/dm3. The pH-value of the samples was adjusted to seven using a standard phosphate buffer. Fluorescence mono-dimensional spectra and total luminescence spectra (TLS) of peat HS were obtained using steady-state fluorescence spectroscopy. All fluorescence spectra were performed on a Horiba Scientific Fluorolog. The fluorescence intensity (IF) values (in CPS) of samples were corrected using method of Lakowicz. Fluorescence coefficients (Milori index and HIX) of HS were calculated from the area of the emission spectra. Biological/autochthonous index (BIX) and fluorescence index (FI) of HS were calculated from the ratio of different emission intensities. Our results showed that the chemical properties of the HS from South-Bohemian peat used in these experiments were well described using seven complementary indexes derived from the ultraviolet-visible and fluorescence spectra (EET/EBz, E250/E365, E465/E665, FI, BIX, Milori index and HIX). Peat HA was characterized high molecular weight, low molecular heterogeneity, high degree of aromatic polycondensation, high level of conjugated fluorophores, and high humification degree. Fulvic acid was characterized and higher content O-containing functional groups (e.g. hydroxyl, carbonyl, ester, especially carboxyl groups on aromatic ring), lower molecular mass, simple structural components of wide molecular heterogeneity, lower degree of aromatic polycondensation, and lower humification degree.

South-Bohemian peat, humic and fulvic acids, absorption and fluorescence coefficients, spectrometric methods

ENEV, V.; NOVÁK, F.; KLUČÁKOVÁ, M.; DOSKOČIL, L.

21. 10. 2014

Masarykova univerzita

Masarykova univerzita, Brno, Česká republika

978-80-210-7159-9

Book of Abstract: CEITEC Annual Conference "Frontiers in Material and Life Sciences"

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