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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Organic compound

Classification: Organic compound -> starch

Citations 2

"Flow System For Starch Determination Based On Consecutive Enzyme Steps And Amperometric Detection At A Chemically Modified Electrode"
Anal. Chem. 1990 Volume 62, Issue 3 Pages 263-268
J. Emneus and L. Gorton

Abstract: A flow injection system is described for the determination of the total glucose content of starch. The system comprises three reactors, in each the required enzyme is immobilized on glutaraldehyde-activated, aminopropyl-silanized controlled-pore glass (CPG) of specific diameter and pore size, these being, respectively, (i) Termamyl 120L (Novo Industri, Denmark), used at 60°C on CPG (75 to 125 µ diameter), (ii) amyloglucosidase, from Aspergillus niger, on CPG (125 to 180 µm) and (iii) porcine mutarotase co-immobilized with glucose oxidase, on CPG (37 to 74 µm). The H2O2 released in (iii) is detected at a graphite electrode with a catalytic layer of Au - Pd (3:2), operated at +0.6 V vs. Ag - AgCl. The carrier flow (0.5 mL min-1) is 0.1 M acetate buffer of pH 5.0 for (i) and (ii) adjusted to pH 7.0 for (iii) by addition of 0.2 M phosphate (pH 7.6). Calibration graphs are rectilinear from 10 µM- to 0.6 mM of glucose with an injection volume of 160 µL and 15 samples h-1 throughput.
Glucose Amperometry Electrode Immobilized enzyme Controlled pore glass Buffer Calibration

"Colorimetric Determination Of β-cyclodextrin: Two Assay Modifications Based On Molecular Complexation Of Phenolphthalein"
J. Biochem. Biophys. Methods 1987 Volume 14, Issue 2 Pages 85-92
Mauri Mäkelä, Timo Korpela and S. Laakso*

Abstract: The decolorization of phenolphthalein on complexation with cyclodextrins was studied as a means of determining β-cyclodextrin. Several factors possibly affecting the shelf-life of the dye were tested. With use of 0.1 M Na2CO3 as assay medium, down to 6 µM-β-cyclodextrin could be determined, and the practical range was up to 60 µM. The method was unaffected by acyclic oligosaccharides and could be used to determine cyclodextrins in complex starch hydrolysates. A further modification of the method is described for use in flow injection analysis, results from which agreed well with those by HPLC.
β-Cyclodextrin Spectrophotometry Complexation Interferences Method comparison