Determination of volatiles in beer using solid-phase microextraction in combination with gas chromatography/mass spektrometry

Abstract

Headspace solid phase microextraction and purge and trap analysis were used for the determination of volatiles in beer. These methods were compared with the analysis of unconcentrated gas phase and liquid extraction. Solid phase microextraction proved to be the most useful and was investigated more closely. Volatiles were isolated by the means of different combinations of sorbents, sorption was performed at various temperatures and times. The addition of salt to the sample and stirring of the sample were examined to enhance the analyte concentration in the gas phase. Ultrasonic bath and filtration were tested to remove carbon dioxide. Not all methods improved the sorption of volatiles. Stirring was characterised by low repeatability and ultrasonic bath causes to the loss of volatile analytes. Distribution constants of volatiles depend on their boiling points and thus different sorption temperatures are suitable for different substances.

Keywords

• gc
• headspace technique
• solid phase
• microextraction
• volatile compounds