title: Infrared spectroscopic studies of the effect of elevated temperature on the association of pyroglutamic acid with clay and other minerals.
abstract: Fourier transform i.r. measurements of L-pyroglutamic acid dispersed in a matrix of a clay, silica or alumina have been obtained at various temperatures between 25 and 220 degrees C.  The i.r. spectrum of L-pyroglutamic acid varies in a manner dependent upon the matrix material and shows considerable change as the temperature of the mixtures is increased.  The differences in the spectrum at elevated temperatures are explained in terms of a chemical reaction between hydroxyl groups in the matrix and the carboxylic acid.  The i.r. spectra of trimethylsilyl derivatives of L-pyroglutamic acid and aluminum pyroglutamate were also measured to assist the understanding of spectra and interpretation of the spectral changes dependent upon increasing temperature.
authors.affiliation: Department of Chemistry, University of Washington, Seattle 98195, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Macklin
authors.forename: D H
authors.initials: DH
authors.lastname: White
mesh_terms: D000537:Aluminum Oxide / Q000032:analysis / Q000737:chemistry*; D000538:Aluminum Silicates / Q000032:analysis / Q000737:chemistry; D000596:Amino Acids / Q000032:analysis / Q000737:chemistry; D001546:Bentonite / Q000032:analysis / Q000737:chemistry*; D000077215:Clay; D006358:Hot Temperature; D007616:Kaolin / Q000032:analysis / Q000737:chemistry; D017616:Magnesium Compounds / Q000032:analysis / Q000737:chemistry; D008903:Minerals / Q000032:analysis / Q000737:chemistry; D011761:Pyrrolidonecarboxylic Acid / Q000032:analysis / Q000737:chemistry*; D017655:Silicon Compounds / Q000032:analysis / Q000737:chemistry; D012822:Silicon Dioxide / Q000032:analysis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D000538:Aluminum Silicates; D000596:Amino Acids; D017616:Magnesium Compounds; D008903:Minerals; D017655:Silicon Compounds; D001546:Bentonite; D007616:Kaolin; D012822:Silicon Dioxide; D000537:Aluminum Oxide; D011761:Pyrrolidonecarboxylic Acid; D000077215:Clay; C026325:attapulgite; C011934:mica