Low-cost multispecies air quality sensor

Field measurements of volatile organic compounds (VOCs) are important in a range of disciplines including air pollution science, medical diagnostics and security screening. There is an enduring need for portable devices that provide reliable compound-specific measurements, at mixing ratios in the part per billion and part per trillion ranges. Such devices should ideally be robust, low-cost and have low-power demands. This work describes the development of a lab-on-a-chip (LOC) device for VOC measurements, a collaboration of multiple disciplines, involving research and development from a number of different fields in sciences and engineering. Such a collaborative approach is necessary for the assembly and integration of sample collection and preparation stages, gas chromatography (GC) separation and photoionisation detection (PID), to create a complete functional system. The objective of this project is to develop a multispecies sensor for measuring hydrocarbons and oxygenated compounds in gas phase samples, through the deployment of thermal desorption methods in combination with a micro-fabricated GC-PID device. The final developed system will allow measurements of a range of different organic compounds in air. This will be validated using controlled experiments and against reference standards and measurement techniques. The system will be applied in number of real-world monitoring investigations, including indoor atmospheres and air pollution studies. In this paper we describe progress towards development of a low power GC chip temperature control system and a low cost PID detector suitable for microfabricated GC