Cereal Chem 63:372-375   |  VIEW ARTICLE
Gas-Chromatographic Determination of Low Concentrations of Propionic Acid in Grain Sorghum.

W. M. Lamkin, N. C. Unruh, and Y. Pomeranz. Copyright 1986 by the American Association of Cereal Chemists, Inc. 

A simple gas-chromatographic procedure was developed for analysis of low concentrations of propionic acid added to prevent fungal growth in high-moisture grain sorghum. After extraction of the propionic acid from the grain into an aqueous solution by using an homogenizer having a shearing action, an aliquot of filtrate was analyzed directly by gas chromatography. Chromatography required only 4 min, and this time could be further reduced if necessary. Over the range of 0.2-0.8% propionic acid, average relative error was less than 1.5% with an average coefficient of variation of less than 1.0%. The method was sufficiently sensitive for the analysis of a single kernel of grain sorghum containing less than 0.03% propionic acid.