K. Pusecker et al., Investigation of hop and beer bitter acids by coupling of high-performanceliquid chromatography to nuclear magnetic resonance spectroscopy, J CHROMAT A, 836(2), 1999, pp. 245-252
HPLC-NMR coupling is becoming used for various applications, including the
analysis of natural products. Its great potential is demonstrated by the an
alysis of hop bitter acids, such as humulones, isohumulones, dihydroisohumu
lones and tetrahydroisohumulones, using on-line and stopped-flow technique
s. H-1-NMR and two-dimensional NMR spectra recorded for all hop bitter acid
s allowed unambiguous identification. It is shown, that hyphenation of HPLC
and NMR spectroscopy offers unique opportunities for analysis and quality
control of hops and beer. (C) 1999 Elsevier Science B.V. All rights reserve
d.