Air pollution has been described by the World Health Organization (WHO) as the largest single environmental health risk and attributes eight million deaths annually as a result of exposure to air pollution. Air is a dynamic matrix and is complex at trace levels. Conventional analytical technologies (such as GC-MS and HPLC) lack the time resolution, responsiveness required to provide timely answers so that the root cause of air quality perturbations can be rapidly identified and addressed. Selected ion flow tube mass spectrometry (SIFT-MS) is a direct mass spectrometric technology for continuous, sensitive, selective, and robust analysis of air. Diverse VOCs (such as benzene and formaldehyde) and inorganic gases (such as sulfur dioxide and hydrogen sulfide) are detected in a single, simple analysis.

Vietnam is thought to be one of the most polluted countries in the world, it has areas of high population density and lower levels of economic development leading to acute air quality issues in its major cities. A recent UK funded project (A Tale of Two Cities) has undertaken observations of a wide range of trace gases in Hanoi using SIFT-MS. This was to provide some of the first ambient organic and inorganic gas phase speciation data in this region.