Effect of a dry purge step on the analysis by dynamic headspace - GC-MS of the volatile fraction of a cheese

Abstract

Abstract. A dry purge procedure was used to eliminate water during the analysis of the volatile fraction of a water-rich cheese, by dynamic headspace-GC-MS. The impact of the duration of this procedure on chromatographic profile was studied for durations ranging from 0 to 50 minutes. A dry purge duration of 3 minutes sufficed to reduce the water peak area and improve the quality of the chromatographic signal. However, the dry purge procedure induced marked modifications to the chromatographic profile of the cheese throughout the range of component polarities.

Needle-type extraction device for the purge and trap analysis of 23 volatile organic compounds in tap water

“…As can be expected, if a large amount of moisture was extracted in the needle and this water was then immediately evaporated in the heated GC injection port by the desorption process, the resulting portion of the analyte could also be purged from the GC injector together with the evaporated large volume of water vapor. This phenomenon has often been observed, and as a result, dry purging has been widely used to remove excess water from the extraction medium, in typical HS and PT analyses [27]. After we confirmed the interference of the moisture during desorption/injection in the GC injector, a purging process with dry N 2 gas was introduced after the sample extraction (Fig.…”

C itrus monstruosa Discrimination among Several C itrus Species by Multivariate Analysis of Volatiles: A Metabolomic Approach

“…) but more recently, the first trapping of head space components followed by thermal desorption, such as for HS‐SPME, was of great interest (Canac‐Arteaga et al . ; Gomes Da Silva and Chaves Das Neves ). In this latter study, in comparison to liquid–liquid extraction, the possible production of artifacts, partial losses of sample during the evaporation step and the sampling time are limited.…”

Analytical artifacts caused by the presence of water vapor in the headspace of food products

“…The analyses (with or without humidifying the headspaces of the samples) were carried out with and without dry purge. The duration of the dry purge step was set at three min with a flow-rate of 60 ml.min -1 [18].…”