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פותח על ידי קלירמאש פתרונות בע"מ -
A quantitative estimation of the complexation of small organic molecules with soluble humic acids
Year:
1997
Source of publication :
Journal of Environmental Quality
Authors :
מינגלגרין, אורי
;
.
Volume :
26
Co-Authors:
Clapp, C.E., USDA-ARS, Dep. of Soil, Univ. of Minnesota, St. Paul, MN 55108, United States
Mingelgrin, U., ARO, Volcani Center, P.O. Box 6, Bet Dagan, Israel
Liu, R., Dep. of Soil, Univ. of Minnesota, St. Paul, MN 55108, United States
Zhang, H., Dep. of Agronomy, Oklahoma State Univ., Stillwater, OK, United States
Hayes, M.H.B., School of Chemistry, Univ. of Birmingham, Edgbaston, United Kingdom
Facilitators :
From page:
1277
To page:
1281
(
Total pages:
5
)
Abstract:
Small organic molecules, such as the commonly used herbicides napropamide [N,N-diethyl-2-(1-naphthyloxy) propionamide] and atrazine (2- chloro-4-ethylamine-6-isopropylamino-1,3,5-triazine), complex with soluble humic acids (HAs), producing a marked effect on apparent solubility, availability, and mobility. The overall objective of the present paper is to propose 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 14C- 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(e) at pH 504, 0.83 and 0.12 mL 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 effects on coiling of the HA strands, which determines the extent of complexation.
Note:
Related Files :
article
Atrazine
Carboxylic acids
controlled study
dialysis
Ground Water
herbicides
Napropamide
soil pollution
עוד תגיות
תוכן קשור
More details
DOI :
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
24492
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:08
Scientific Publication
A quantitative estimation of the complexation of small organic molecules with soluble humic acids
26
Clapp, C.E., USDA-ARS, Dep. of Soil, Univ. of Minnesota, St. Paul, MN 55108, United States
Mingelgrin, U., ARO, Volcani Center, P.O. Box 6, Bet Dagan, Israel
Liu, R., Dep. of Soil, Univ. of Minnesota, St. Paul, MN 55108, United States
Zhang, H., Dep. of Agronomy, Oklahoma State Univ., Stillwater, OK, United States
Hayes, M.H.B., School of Chemistry, Univ. of Birmingham, Edgbaston, United Kingdom
A quantitative estimation of the complexation of small organic molecules with soluble humic acids
Small organic molecules, such as the commonly used herbicides napropamide [N,N-diethyl-2-(1-naphthyloxy) propionamide] and atrazine (2- chloro-4-ethylamine-6-isopropylamino-1,3,5-triazine), complex with soluble humic acids (HAs), producing a marked effect on apparent solubility, availability, and mobility. The overall objective of the present paper is to propose 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 14C- 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(e) at pH 504, 0.83 and 0.12 mL 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 effects on coiling of the HA strands, which determines the extent of complexation.
Scientific Publication
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