HIGH SENSITIVITY AND SPECIFICITY MONITORING OF GASEOUS VOCS COUPLING A MULTIPASS GAS CELL SETUP WITH FTIR SPECTROSCOPY AND MACHINE LEARNING

Here, we will discuss the development of a new, and highly sensitive sensor system based on Infrared (IR) spectroscopy able to measure very low concentrations of various VOCs down to sub-ppm level and to discriminate among different chemical species, differently from currently used detectors, such as gas semiconductor sensors, gas chromatography, and/or mass spectrometry, photo- ionization detectors (PID), and so on. We will present the experimental setup, its performances, and the procedure to measure VOCs concentration from their IR absorbances. The calibration curves for different VOCs are carried out, namely, styrene and several co-products (such as acetone, ethanol, isopropanol, benzene, toluene and xylene). The use of the calibration curves provides a reliable method to obtain sub-ppmv concentrations well below the PID detection capability, as observed, in particular for styrene.