Seperation of hop bitter acids by capillary zone electrophoresis and micellar electrokinetic chromatography with UV‐diode array detection

Stir bar sorptive extraction‐liquid desorption applied to the analysis of hop‐derived bitter acids in beer by micellar electrokinetic chromatography

“…Problems related with interaction of the solutes with trace metals in the chromatographic system resulting in poor resolution and quantitation have been reported [2,8]. Electrodriven separation techniques such as micellar electrokinetic chro-matography (MEKC) [9,10], microemulsion electrokinetic chromatography (MEEKC) [11], and capillary electrochromatography (CEC) [12] have been evaluated for the analysis of the hop acids while the iso-a-acids were successfully separated by MEKC [13,14]. For the analysis of the iso-a-acids in beer, a preconcentration step is normally performed, although direct injection of beers with stacking has been described [15].…”

Simultaneous analysis of hop acids and prenylated flavanones by microemulsion electrokinetic chromatography with diode array detection

“…Fast and efficient separation was achieved via micellar electrokinetic chromatography (MEKC), but the repeatability of the separation between lupulone and adlupulone proved to be poor (Vindevogel et al, 1990). The narrow pH interval, in which the separation occurs, appeared to be the most subtle factor.…”

Single-run capillary electrochromatographic analysis of hop acids and prenylated hop flavonoids

“…Previously, hop acids have been analysed by capillary zone electrophoresis (CZE), resulting in group separation of a-and b-acids, while individual components were not resolved [4]. Fast and efficient separation was achieved by micellar electrokinetic chromatography (MEKC), but the repeatability of the separation of the critical pair lupulone/adlupulone was poor due to the narrow pH-interval [4].…”