Development of formaldehyde flux sampler using a commercial DNPH cartridge

摘要

Building materials and consumer products are main sources of formaldehyde emitted in non-smoking environments. Identifying major emitters in existing buildings is difficult since the emission factors (EFs) are typically determined in a chamber test that is not suitable for on-site measurement. In this study, a new passive flux sampler (PFS) was developed for on-site measurement of formaldehyde EFs from building materials. The PFS is non-invasive and suitable for a long-term test (4?7 days) that is based on a commercially available 2,4-dinitrophenylhydrazine (DNPH) cartridge. Five designs of PFS with different diffusion lengths and diameters were tested with 8 composite wood products (CWPs). The PFS with a diffusion length of 20 mm and a diameter of 10 mm (PFS-D1) was shown to have the EFs comparable to those from conventional chamber tests. Laboratory tests showed that the PFS-D1 has acceptable variability (21% of relative standard deviation) and sensitivity that can collect mass above detection limit for 4?7 day sampling. The PFS-D1 was used to determine EFs of 5?9 CWPs in a research house at 3 and 8 months after construction. The EFs were used to predict the indoor formaldehyde concentration, which led to good agreement (?25%) with the measured concentration. The major emitters were determined to be CWPs such as floor and door, indicating that PFS-D1 is a useful tool to identify and prioritize formaldehyde sources in existing buildings.