Assessment of diffusion parameters of new passive samplers using optical chemical sensor for on-site measuring formaldehyde in indoor air: Experimental and numerical studies

摘要

New passive samplers using a sensor consisting of a sol-gel matrix entrapping Fluoral P as sampling media were developed for the determination of formaldehyde in indoor air. The reaction between Fluoral P and formaldehyde produces a coloured compound which is quantified on-site by means of a simple optical reading module. The advantages of this sensor are selectivity, low cost, ppb level limit of detection and on-site direct measurement. In the development process, it is necessary to determine the sampling rate, a key parameter that can not be directly assessed in the case of diffusive samplers using optical chemical sensor. In this study, a methodology combining experimental tests and numerical modeling is proposed and applied at five different radial diffusive samplers equipped with the same optical chemical sensor to assess the sampled material flows and sampling rates.