Separation of α-, β- and iso-α-acids in hop products and beer by high-performance liquid chromatography

Avoidance of trace metal activity with micro-liquid chromatography in the analysis of hop and beer bitter acids

Packed fused-silica columns (250 X 0.32 mm I.D.) or micro-liquid chromatographic (LC) and more usual columns in stainless steel (250 X 4.6 mm I.D.) or "conventional LC" are compared for the quantitation of hop and beer bitter compounds. For the hop alpha- and beta-acids the difference is not significant. A slight preference for micro-LC can be argumented on the fact that this system will more readily show the presence of deoxy-alpha-acids. For the iso-alpha-acids the inert character of micro-LC using packed fused-silica columns is essential for good results. It is believed that the inert character of micro-LC would benefit many other analytical problems of complex natural organic compound mixtures.