Odorous compounds, such as carbonyl substances, play a major role in ambient air pollution. Monitoring these VOCs is important because some of them have adverse effects on human health and the environment or are, at least, responsible for unpleasant smells. Due to the large number of molecules potentially analyzed, it is difficult to separate and quantify precisely all compounds using a chromatograph equipped with a non-specific detector. The goal of this study is to perform automatic and continuous identification and quantification of odorous VOCs using two different Thermal-Desorption Gas Chromatographs equipped with two Flame Ionization Detectors (FID) and one Mass Spectrometer (MS). Each system is designed with its specific analytical conditions, one for monitoring light compounds and the other for heavier compounds. The coupling of two different TD-GC-FIDs to a Quadrupole MS, allows the automatic identification of coeluted compounds by MS and the quantification of the non-coeluted ones by FID.
An algorithm has been developed in the software to select the more accurate result between this dual detection. To achieve this automatic reprocessing, the implementation of validation parameters was developed for each identified compound, while remaining adaptable and verifiable if necessary. This fully automatic system allows non-specialist operators to access expertise level results.