VIEW ARTICLE    DOI: 10.1094/ASBCJ-37-0180

HPLC of Hop Acids on Buffered Silica Gel Systems. Rolf Schwarzenbach, Givaudan Research Company Ltd., Ueberlandstrasse 738, CH-8600 Dübendorf, Switzerland. J. Am. Soc. Brew. Chem. 37:0180, 1979.

High performance liquid chromatography provides a fast alternate method for the separation and determination of hop acids. Most previous chromatographic separations are accompanied by long retention times and poor resolution. Experiments have shown that an acidic environment on the surface of the silica gel is essential for elution without tailing. To fulfill this requirement, the silica gel was coated with a buffer salt. This article describes the influence of the type, pH, and concentration of the buffer solution used to modify the silica gel, the changes in separation selectivity, and the application of such buffered silica gel systems for the analysis of hop extracts, isomerized hop extracts, and beer.

Keywords: α-Acid, Adsorption, Chromatography, Ion exchange, Iso- α-acid