Use of the AutoAnalyzer for determining the blue value of the amylose-lodine complex and total carbohydrate by phenol-sulfuric acid

✍ Scribed by John F. Robyt; Sandra Bemis

• Publisher: Elsevier Science
• Year: 1967
• Tongue: English
• Weight: 212 KB
• Volume: 19
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(67)90133-9

✦ Synopsis

Measurement

of the blue color of the amylose-iodine complex in aqueous solution (blue value) has been widely used to determine the amount of amylose present in a starch sample (1, 2) and has been employed in measuring changes in the amylose molecule due to hydrolysis by amylases (3). We have used the measurement of the blue value extensively in cY-amylolysis studies of amylose and starch.

The measurement of total carbohydrate by the phenol-sulfuric acid procedure (4) has also been widely employed in our enzymic work and in the analysis of various fractions from the chromatographic separation of maltodextrins on paper and on charcoal and Sephadex columns. Although procedures have been published for the automated analysis of total carbohydrate by acid hydrolysis with subsequent reducing value measurement (5) and by the anthrone procedure (6), we have preferred the phenol-sulfuric acid procedure because of its simplicity, greater sensitivity for low concentrations of carbohydrate (10-180 pLg/ml), and high solubility of phenol in water as compared with the very low solubility of anthrone in water.

The use of the Technicon AutoAnalyzer has been shown to increase the reliability of an analytical determination by reducing the systematic and indeterminate errors; it also permits relative ease of analysis and greatly increases the number of samples that may be analyzed. Thus, we have adapted the blue value procedure of McCready and Hassid (2) and the phenol-sulfuric acid procedure (4) to the Technicon AutoAnalyzer and present these adaptations here.