An Overview of VOC Sampling and Detection Techniques

Volatile Organic Compounds (VOCs) are the key air pollutants that act as precursors to major secondary pollutants including tropospheric ozone and secondary organic aerosols (SOA) and various health issues. Therefore, there is a need to have a simple, portable, reliable sampling method to quantify VOCs. This study reviews VOC sampling techniques based on feasibility, the material used, sensors and gas chromatographic instruments. A particular highlight on VOC sensors concerning their sensitivity, detection limit, response time and robustness has also been done. Also, the study focuses on critical aspects of VOC characterisation in ambient air along with the advantages and challenges of the methods. Around 65% of researchers have used the gas chromatography-based FID technique (GC-FID) for VOC characterisation in India. The typical sampling methods used in India are sorbent tubes or cartridges, air sample bags (commonly Tedlar bags), glass air sampling units and canisters. The portable real-time method is also used. The most common sampling method is passive sampling with sorbent tubes with activated carbon. However, extensive research is required on more sophisticated and world-class sensors, sampling and detection techniques to reach safe and recommended targets.