SSSAJ Grow Your Career with SSSA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Published in Soil Sci Soc Am J 54:78-86 (1990)
© 1990 Soil Science Society of America
677 S. Segoe Rd., Madison, WI 53711 USA
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sikora, F. J.
Right arrow Articles by McBride, M. B.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Sikora, F. J.
Right arrow Articles by McBride, M. B.
Agricola
Right arrow Articles by Sikora, F. J.
Right arrow Articles by McBride, M. B.

Aluminum Complexation by Protocatechuic and Caffeic Acids as Determined by Ultraviolet Spectrophotometry

F. J. Sikora*

NFD 1F 132A, Tennessee Valley Authority, Muscle Shoals, AL 35660

M. B. McBride

Dep. of Agronomy, Cornell Univ., Ithaca, NY 14853

* Corresponding author.

ABSTRACT

Ultraviolet (UV) spectrophotometry was used to study the complexation of Al by protocatechuic and caffeic acids at pH 3.8 to 4.5. The stoichiometry of the Al-organic acid complex was found to be 1:1 through Job's method of continuous variation in the pH range studied. Increased pH and Al concentrations resulted in bathochromic shifts in the UV spectra of the organic acids due to the formation of an Al-organic complex absorbing UV radiation differently than the free organic. Aluminum was concluded to be chelated by the ortho-hydroxy group of the organic acids, as opposed to carboxyl-group binding. The deprotonation of the carboxyl group in the free organic and Al-organic complex had to be considered in the calculation of association constants. Association constants of 1015.33 and 1015.06 for protocatechuic and caffeic acids, respectively, were determined by Al titrations. Calculated absorbance as a function of pH agreed well with experimental titrations. Application of the determined association constants to a simplified model of a forest soil solution is presented.

NOTES

Contribution from Dep. of Agronomy, Cornell Univ. Project supported by National Science Foundation Grant EAR-8512226.

Received for publication March 7, 1989.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Agronomy Journal Crop Science
Journal of Natural Resources
and Life Sciences Education		 Vadose Zone Journal
Journal of Plant Registrations Journal of
Environmental Quality		 The Plant Genome
Copyright © 1990 by the Soil Science Society of America.