GC-O is a powerful technique able to combine analytical results arising from GC/MS and sensorial perception. Recently introduced Olfactory Detection Port 4 (ODP4), by Gerstel, consists of a dual-detection system, pushing such combination of analytical and sensorial results to a new level of reliabilty.
A sample injected in a standard GC sistem is diverted at the end of the column by means of splitting device: part of the effluent reaches the MS detector, while a second aliquote is directed to an olfactometric port where a trained operator sniffs in a proper way.
The two traces (i.e. chromatogram and olfactogram) are then overlayed to combine
sensorial and analytical results.
It often happens that coeluting compounds are not clearly detectable either by detector or operator; such situation can be elegantely fixed using the S&T option provided by Gerstel ODP4.
Briefly, instead of a funnel suitable for sniffing, at the ODP exit is installed a desorbtion tube able to trap the analytes. Such tube is then desorbed in a GC/MS system where a different column is used: this allows to separate the previously eluting compounds in order to identify them.
A further improvement is related to the new Gerstel ODI2, wich provides a streamlined GC-O data processing workflow, featuring deconvolution followed by RI-MS library search and compatibility with commercial and user-generated databases