Clays and Clay Minerals, Vol. 55, No. 4, 361–368, 2007.
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Authors
Kawano, Motoharu
Obokata, Sumine
Issue Date
2007
Type
Article
Language
Keywords
Periodicals , Geology , Amino Acids , Amorphous Silica , Biological Molecule , Dissolution Rate , Mineral Dissolution
Alternative Title
The Effect Of Amino Acids On The Dissolution Rates Of amorphous Silica In Near-neutral Solution
Abstract
Amino acids are ubiquitous in the Earth’s surface environments as reactive biological molecules produced by every living thing including bacteria. To evaluate the effects of amino acids on mineral dissolution and to reveal the mechanism by which they interact with the mineral surface, we performed dissolution experiments of X-ray amorphous silica in solution containing 0.1 mmol Na with 10.0 mmol amino acids such as cysteine, asparagine, serine, tryptophan, alanine, threonine, histidine, lysine and arginine in near-neutral solutions. Dissolution experiments in solutions of 0.1, 1.0 and 10.0 mmol NaCl without amino acids were also conducted as amino acid-free controls. The results of this study indicate that basic aminoacids such as histidine, lysine and arginine can interact more strongly with the negatively charged surface of amorphous silica than other non-basic amino acids due to their greater dissociation, thus forming cationic species. This electrostatical interaction enhanced dissolution rates of amorphous silica by approximately one order of magnitude compared with amino acid-free controls. In contrast, no significant effect on the dissolution rates of amorphous silica was observed in solutions containing cysteine, asparagine, serine, tryptophan, alanine and threonine because of lesser interaction with the surface of amorphous silica.
Description
Clays and Clay Minerals, Vol. 55, No. 4, 361–368, 2007. The Effect Of Amino Acids On The Dissolution Rates Of Amorphous Silica In Near-neutral Solution. Motoharu Kawano; Sumine Obokata. DOI: 10.1346/CCMN.2007.0550404. Copyright © 2007, The Clay Minerals Society
Citation
Clays and Clay Minerals, Vol. 55, No. 4, 361–368, 2007.
Publisher
The Clay Minerals Society
License
Copyright © 2006-2018, The Clay Minerals Society