University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Biological tissue -> intestine -> rat

Citations 2

"High Performance Liquid Chromatographic Determination Of Nicotinic Acid And Nicotinamide In Biological Samples Applying Post-column Derivatization Resulting In Bathmochrome Absorption Shifts"
J. Chromatogr. B 1995 Volume 665, Issue 1 Pages 71-78
J. Stein*, A. Hahn and G. Rehner

Abstract: An ion-pair reversed-phase high performance liquid chromatographic procedure for the rapid separation and sensitive quantitation of nicotinic acid (NA) and nicotinamide (NAM) in biological samples was developed. The vitamers were separated within 10 min on an octadecylsilica column applying a linear gradient of tetrabutylammonium phosphate and methanol. NA and NAM were converted to highly absorbing derivatives by a modified Konig's reaction using a double post-column derivatization arrangement consisting of two pumps and two knitted tubular reactors. The proposed method is highly sensitive and specific and applicable to biological materials as was shown by the analysis of rat intestinal tissue.
Nicotinic acid Nicotinamide HPLC Spectrophotometry Post-column derivatization Knotted reactor

"Automated Continuous-flow Procedure For Determination Of Enterokinase"
Clin. Chim. Acta 1979 Volume 98, Issue 3 Pages 187-194
J. P. Vaultier, R. Eloy*, A. Hoeltzel and J. F. Grenier

Abstract: A continuous flow method has been developed for the automatic determination of enterokinase in rat small intestine mucosa and/or luminal content. Trypsinogen was first hydrolyzed by enterokinase under conditions which minimize autocatalytic activation. L-benzoyl-arginine paranitroanilide was then added and split to paranitroaniline by the trypsin so formed. Liberated paranitroalinine was diazotized and converted by the Bratton-Marshall reagent (N-naphthyl ethylene diamine) to an azodye, with maximum absorption at 550 nm. This method of determination was found to be six times more sensitive than the direct p-nitroaniline determination method. 36 determinations can be made hourly.
Enzyme, enterokinase Enzyme, enteropeptidase Clinical analysis Spectrophotometry