Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
A QUANTITATIVE ESTIMATION OF THE COMPLEXATION OF SMALL ORGANIC-MOLECULES WITH SOLUBLE HUMIC ACIDS
Autore:
CLAPP CE; MINGELGRIN U; LIU R; ZHANG H; HAYES MHB;
Indirizzi:
UNIV MINNESOTA,USDA ARS ST PAUL MN 55108 UNIV MINNESOTA,DEPT SOIL WATER & CLIMATE ST PAUL MN 55108 AGR RES ORG,VOLCANI CTR IL-50250 BET DAGAN ISRAEL UNIV MINNESOTA,DEPT SOIL WATER & CLIMATE ST PAUL MN 55108 OKLAHOMA STATE UNIV,DEPT AGRON STILLWATER OK 74078 UNIV BIRMINGHAM,SCH CHEM EDGBASTON ENGLAND
Titolo Testata:
Journal of environmental quality
fascicolo: 5, volume: 26, anno: 1997,
pagine: 1277 - 1281
SICI:
0047-2425(1997)26:5<1277:AQEOTC>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
SOIL; PESTICIDES; ADSORPTION; SUBSTANCES; MATTER;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
19
Recensione:
Indirizzi per estratti:
Citazione:
C.E. Clapp et al., "A QUANTITATIVE ESTIMATION OF THE COMPLEXATION OF SMALL ORGANIC-MOLECULES WITH SOLUBLE HUMIC ACIDS", Journal of environmental quality, 26(5), 1997, pp. 1277-1281

Abstract

Small organic molecules, such as the commonly used herbicides napropamide [N,N-diethyl-2-(1-naphthyloxy) propionamide] and atrazine oro-4-ethylamino-6-isopropylamino-1,3,5-triazine), complex with soluble humicacids (HAs), producing a marked effect on apparent solubility, availability, and mobility. The overall objective of the present paper is topropose a procedure by which the extent of complexation of small organic molecules with stable humic acids can be quantitatively estimated. Experiments were carried out to investigate the effects of HA and herbicide concentrations, pH, and ionic composition and strength on the extent and nature of complexation using an equilibrium dialysis procedure and C-14-labeled herbicides. The relative strength of complexes of napropamide with a series of HAs from a wide range of sources, determined at a concentration of 2.0 mg HA mL(-1), was in the order of soil >peat > water. Complexation of the herbicides with the soil HA was greater for napropamide than for atrazine (K-c at pH 6.5, 0.83 and 0.12 mt mg(-1), respectively). As solubility of molecules In water increases, complex formation usually decreases. However, the complexation of napropamide and atrazine did not correlate inversely with their solubility. Environmental conditions, such as pH and ionic strength and composition, as well as the source of the HAs, had a strong effect on the complexation of the investigated pesticides. The relationship between complexation and the above factors suggests that it is their effect on coiling of the HA strands, which determines the extent of complexation.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/12/20 alle ore 14:38:31