Publication detail

Conformational behavior of lignite humic fractions separated by sequential pH-extractions

KUČERÍK, J., CONTE, P., PEKAŘ, M., PICCOLO, A.

Original Title

Type

journal article - other

Language

English

Original Abstract

A bulk humic acid (HA) extracted from a South Moravian lignite was further fractionated by sequential extraction in buffers at different pHs. All samples were analyzed by high performance size exclusion chromatography (HPSEC) and elemental analysis. Weight-averaged molecular weights (Mw) of fractions dissolved at pH 7, 8, and 9 were larger than for the parent bulk HA, thereby indicating that Mw of humic matter is related only to molecular size as affected by sample hydration rather than its molecular mass. Moreover, hydration radius was a function of the specific chemical properties of humic fractions. Addition of small amount of either mineral (HCl) or organic acid (formic, acetic, propionic) to humic solutions induced significant changes in conformational arrangements of the treated sample in respect to control. Also the conformational changes among humic fractions depended on their different molecular composition and suggested a weakly-bound supramolecular association of different humic molecules in solution.

Keywords

humic substances, lignite, HPSEC

Authors

KUČERÍK, J., CONTE, P., PEKAŘ, M., PICCOLO, A.

RIV year

2003

Released

1. 1. 2003

ISBN

1018-4619

Periodical

Fresenius Environmental Bulletin

Year of study

Number

State

Federal Republic of Germany

Pages from

683

Pages to

689

Pages count

BibTex

@article{BUT41503,
  author="Jiří {Kučerík} and Pelegrino {Conte} and Miloslav {Pekař} and Alessandro {Piccolo}",
  title="Conformational behavior of lignite humic fractions separated by sequential pH-extractions",
  journal="Fresenius Environmental Bulletin",
  year="2003",
  volume="12",
  number="7",
  pages="7",
  issn="1018-4619"
}