Analysis of beer iso‐α‐acids by micellar electrokinetic chromatography and multi‐wavelength UV detection

Abstract

The identification of beer bitter acids in a pre‐isomerized hop extract by means of their UV‐spectra is described. Preliminary data for the analysis of these compounds in beer samples are presented.

Reproducibility of migration times and propagation of error in micellar electrokinetic chromatography

“…Iso-u-acids werb analyzed as reported previously [5]. Conditions were the same, except that a 30 mM phosphate buffer (PH 7.6) with 30 or 50 mM SDS was used and the detection wavelength was 254 nm.…”

Analysis of iso-α-acids and reduced iso-α-acids in beer by direct injection and liquid chromatography with ultraviolet absorbance detection or with mass spectrometry

“…Enrichment is commonly carried out by liquid-liquid extraction or by solid phase extraction (SPE) on reversed phase material [8,9,[12][13][14]. Recently, the application of a new solventless extraction method named stir bar sorptive extraction (SBSE) has been described [15].…”

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].…”

“…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]. Enrichment is commonly carried out by liquid-liquid extraction or by solid-phase extraction on reversed-phase material [13,15,16]. Recently, a new solventless extraction method named stir bar sorptive extraction (SBSE) has been described [17].…”