Abstract: Iso-α-acids content of isomerized hop pellets was analyzed by reversed-phase high performance liquid chroma- tography (RP-HPLC). The optimized conditions are: 270 nm by ultraviolet detection with methanol: H2O: H3PO4 (85%): EDTA- Na2 (0.2 mol/L) (770: 210: 5: 1, respectively) as mobile phase with flow rate 1.0 ml/min. The average recovery of iso-α-acids is 91.4 %～97.1%, and the accuracy of the method as RSD (relative standard deviation) is about 1.09 %. The column is EC 250/ 4 Nuclesoil, 100-5 C18 (4.0×250 nm, 5μm) with Guard Cartridge CC 8/4 Nuclesoil 100-5 C18. It is a convenient and accurate method for analyzing iso-α-acids content in isomerized hop pellets.

Key words: iso-&alpha, -acids； isomerized hop pellets； RP-HPLC；