Headspace is a common approach used for analysing VOCs from aqueous samples or solids. Heating and agitation of the sample in a sealed vial releases volatiles from non-volatile matrix, and after equilibrium is reached the headspace gas is sampled and injected into the GC or GC–MS using a heated syringe.
The Centri system from Markes International fully automates both regular headspace sampling and headspace–trap, with cryogen-free focusing. Headspace–trap results in enhanced sensitivity by larger injection volumes and multiple extraction cycles from a single sample to be ‘concentrated’ in one GC–MS run, as well as improved peak shape and optional sample splitting and re-collection for repeat analysis without the need to repeat extraction steps.
