University of Lancashire Proton Transfer Reaction-Time of Flight- Mass Spectrometer (PTR-ToF-MS) provides online measurements of volatile organic compounds in air with a high time resolution and low limit of detection. The time of flight mass analyser enables all compounds which undergo ionisation through reaction with H3O+ to be monitored simultaneously. The instrument deployed during the Atmospheric Pollution & Human Health in a Chinese Megacity programme (APHH-Beijing) field campaigns was a Ionicon PTR 2000 provided by the Guangzhou Institute of Geochemistry.

The PTR-ToF-MS is described in detail by Jordan A., Haidacher S., Hanel G., Hartungen E., Märk L., Seehauser H., Schottkowsky R., Sulzer P. and Märk T.D. (2009). A high resolution and high sensitivity proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). International Journal of Mass Spectrometry, 286, 122-128.