Publication detail

Polarity-Based Sequential Extraction as a Simple Tool to Reveal the Structural Complexity of Humic Acids

ENEV, V. SEDLÁČEK, P. KUBÍKOVÁ, L. SOVOVÁ, Š. DOSKOČIL, L. KLUČÁKOVÁ, M. PEKAŘ, M.

Original Title

Polarity-Based Sequential Extraction as a Simple Tool to Reveal the Structural Complexity of Humic Acids

Type

journal article in Web of Science

Language

English

Original Abstract

A sequential chemical extraction with a defined series of eluotropic organic solvents with an increasing polarity (trichloromethane < ethyl acetate < acetone < acetonitrile < n-propanol < methanol) was performed on peat-bog humic acid. Six organic fractions were obtained and subjected to a physicochemical characterization utilizing methods of structural and compositional analysis. Advanced spectroscopic techniques such as Attenuated Total Reflectance (ATR-FTIR), total luminescence, and liquid-state 13C NMR spectrometry were combined with elemental analysis of the organic fractions. In total, the procedure extracted about 57% (wt.) of the initial material; the individual fractions amounted from 1.1% to 19.7%. As expected, the apolar solvents preferentially released lipid-like components, while polar solvents provided organic fractions rich in oxygen-containing polar groups with structural parameters closer to the original humic material. The fraction extracted with acetonitrile shows distinct structural features with its lower aromaticity and high content of protein-like structural motifs. The last two—alcohol extracted—fractions show the higher content of carbohydrate residues and their specific (V-type) fluorescence suggests the presence of plant pigment residues. The extraction procedure is suggested for further studies as a simple but effective way to decrease the structural complexity of a humic material enabling its detail and more conclusive compositional characterization.

Keywords

transitional peat-bog; Eutric Histosol; humic acid; organic fraction; sequential chemical extraction; absorption parameters; FTIR; excitation-emission matrix; 13C NMR; aromaticity; molecular weight

Authors

ENEV, V.; SEDLÁČEK, P.; KUBÍKOVÁ, L.; SOVOVÁ, Š.; DOSKOČIL, L.; KLUČÁKOVÁ, M.; PEKAŘ, M.

Released

19. 3. 2021

Publisher

MDPI

Location

Basel, Switzerland

ISBN

2073-4395

Periodical

Agronomy

Year of study

11

Number

3

State

Swiss Confederation

Pages from

1

Pages to

19

Pages count

19

URL

https://www.mdpi.com/2073-4395/11/3/587

Full text in the Digital Library

http://hdl.handle.net/11012/196739

BibTex

@article{BUT170991,
  author="Vojtěch {Enev} and Petr {Sedláček} and Leona {Kubíková} and Šárka {Bačovská} and Leoš {Doskočil} and Martina {Klučáková} and Miloslav {Pekař}",
  title="Polarity-Based Sequential Extraction as a Simple Tool to Reveal the Structural Complexity of Humic Acids",
  journal="Agronomy",
  year="2021",
  volume="11",
  number="3",
  pages="1--19",
  doi="10.3390/agronomy11030587",
  issn="2073-4395",
  url="https://www.mdpi.com/2073-4395/11/3/587"
}