Development of on-line and Field Dual TD-GC-FID/MS for Automatic and Continuous Volatile Organic Compounds (VOCs) Ambient Air and Odour Monitoring

摘要

Ambient air is polluted by many Volatile Organic Compounds (VOCs) coming from anthropogenic and naturalsources. VOCs from PAMS, TO14 and TO15 lists can be measured in many ranges of concentration, fromng/m~3 up to mg/m~3 depending on the location of the measurements. Due to the large number of molecules,the complete separation of all compounds is difficult to perform using chromatographic columns. Therefore, itis difficult to quantify precisely all compounds using a chromatograph equipped with a nonspecific detector.The goal of this study is to perform automatic and continuous identification and quantification of VOCs using adual Thermal-Desorber Gas Chromatograph equipped with two Flame Ionization Detectors (FIDs) and oneMass Spectrometer (MS). The device is required to identify automatically coeluted compounds by MStechnology adapted to industrial context. The coupling of two different TD-GC-FIDs to a Quadrupole MSallowed by an elaborated multiplexer system is the originality of the project: one TD-GC-FID for monitoring oflight compounds and one for heavy compounds with specific analytical conditions for each system. Ameasurement campaign in petrochemical new site shows the concentration of about 100 compounds atdifferent steps of the commissioning. Thanks to the continuous measurements every 30 minutes, variations ofconcentrations during specific hours can be monitored. Potentially coeluted compounds like terpenes ororganochlorinated are identified and monitored at ppt level. This solution enables to monitor odorantscompounds at level of concentration lower than what human nose can detect. It also offers good capabilitiesfor odour monitoring with molecule speciation. This fully automatic system allows non-specialist operators toaccess expertise level results.