THEORETICAL DETERMINATION OF THE SAMPLING RATES OF DIFFUSION SAMPLERS FOR VOCS AND ALDEHYDES

摘要

This study attempted to derive the sampling rate (SR) for diffusion samplers from the geometry (diffusion area and diffusion length) of the samplers and the physical properties of volatile organic compounds (VOCs) based on Fick's law of diffusion. We tested seven types of diffusion aldehyde samplers and eleven types of diffusion VOC samplers marketed in Japan. SRs were also determined experimentally using simultaneous active (pump) and diffusion sampling. Vapor diffusion was used to generate a stable concentration of sample VOC and aldehyde gases of known concentrations, which were introduced into a 350 L chamber. Each sampler was exposed in the chamber for a specified period. For most samplers and most VOCs, the theoretically determined SRs were nearly the same as the experimentally established SRs. Thus, accurate calculation of SRs for VOCs based on the diffusion theory seems possible without the need to perform experimental measurements.