Enhanced selectivity VOC detection using novel GC-QEPAS

ongoing

Volatile organic compounds (VOCs) are organic chemicals that have a high vapor pressure at room temperature. Based on their origin and formation mechanisms, VOCs can be markers in many industrial processes; in food production as quality markers, technological indicators, process contaminants; in plant phenotyping as botanical/geographical tracers, authenticity markers; and in crops storage as shelf-life indicators. VOCs also pose a range of hazards to human health and the environment. EVOQUE’s main objective is to develop a novel photonic-based sensory system with potential to outperform the current standards and to meet the challenging requirements of at-line, on-line & in-field needs of Agriculture, Food, Environmental Pollution monitoring and Industrial Emissions monitoring. EVOQUE will combine gas chromatography (GC), Quartz Enhanced Photo-Acoustic Spectroscopy (QEPAS), long wavelength quantum cascade lasers (QCLs) and mid-IR metasurfaces to produce a compact, easy to use, low cost, at-line and ultimately online, field deployable VOCs analyser that will have equivalent performance to the gold standard lab based GC-MS. EVOQUE will leverage GC’s separation of components from complex mixtures, and QEPAS’s high sensitivity, specificity and quantification. Unlike simpler GC detectors, QEPAS will provide molecular recognition based on the specific spectral features of single VOCs. The system measures the target compound even in presence of interferents, thus avoiding issues with poor repeatability of elution times and reducing the false positive rate relative to GC with non-specific detectors. Also, optical spectroscopy of many VOCs is hampered by absorption by atmospheric compounds at the wavelengths of interest or overlapping absorption features of related molecules; using the GC column, these compounds are separated and eluted from the column at different times, thus unleashing the potential of photonics for sensitive fast, non-destructive measurements of VOCs.