VIEW ARTICLE    DOI: 10.1094/ASBCJ-57-0055

Preparation of Isomerized alpha-Acid Standards for HPLC Analysis of Iso-alpha-Acids, rho-Iso-alpha-Acids, Tetrahydro-Iso-alpha-Acids, and Hexahydro-Iso-alpha-Acids. John Paul Maye, Susie Mulqueen, Scot Weis, Jianping Xu, and Matthew Priest (1), Haas Hop Products, Inc., Milwaukee, WI 53212. (1) Currently employed at Pfizer Inc. in Groton, Connecticut. J. Am. Soc. Brew. Chem. 57(2): 55-59, 1999. Accepted February 8, 1999.

Simple and convenient methods for making stable isomerized alpha-acid standards for the HPLC analysis of iso-alpha-acids, rho-iso-alpha-acids, tetrahydro-iso-alpha-acids, and hexahydro-iso-alpha-acids are demonstrated. These HPLC standards are produced using the commercially available products as starting materials. The iso-alpha-acid, rho-iso-alpha-acid, and hexahydro-iso-alpha-acid standards are dicyclohexylamine salts. The tetrahydro-iso-alpha-acid standards are prepared by simple recrystallization from hexane. Keyword: Dicyclohexylamine.

Métodos simples y convenientes para preparar estándares estables de ácidos de lupulo isomerizado para el análisis por HPLC de iso-alfa-acidos, rho-iso-alfa-ácidos, tetrahidro-iso-alfa-ácidos y hexahidro-iso-alfa-ácidos son demostrados. Esos estándares HPLC son producidos usando los productos comercialmente disponibles como materiales iniciales. Los estándares de iso-alfa-ácido, rho-iso-alfa-ácido y hexahidro-iso-alfa-ácido son las sales con diciclohexilamina. Los estándares de tetrahidro-iso-alfa-ácido son preparados por simple recristalización de hexano. Palabra clave: Diciclohexilamina.