Comparison of the standard method with the portable PID method determining indoor air totaol volatile organic compounds (TVOC)

The paper compared the Chinese National Standard Method by using of thermal desorption/capcillary gas chromatography (FID) with the direct reading method by using of portable PID instrument for determining indoor air total volatile organic compounds(TVOC) both in laboratory and on site. It is found that in the environment where there is only simple pollutants or the composition is under control, the two methods have some correlation after necessary calibration. while, to the complicated samples which are mixed by many pollutants, it is very difficult for qualitative analysis, so there is nearly no relationship between them. Additionally, the data from PID will have large error at high humidity due to its own inherent characteristics. The PID portable device can be applied in emergency to detect and judge pollution source and to measure real-time concentrations of organic compounds to acquire concentration decline along with the time and spatial distribution.