Impregnated Filters for the Determination of Formaldehyde in Indoor Environments.

摘要

New techniques for the collection of formaldehyde (HCHO) at ppB-ppM concentrations in air are reported. HCHO samples are collected on filters impregnated with sodium bisulfite in either an active or passive (diffusional) sampling mode. HCHO reacts with sodium bisulfite to form a stable addition product. Samples are analyzed by a promulgated analytical method. The average collection efficiency of the filters in the active sampling mode is 101 +- 5.6% and concentrations as low as 10 ppB may be detected in an 80-L air sample. The passive monitors collected HCHO linearly over a range of concentrations from 0.05 to 1.0 ppM. In a sampling period of 100 hrs, 100 ppB of HCHO may be detected with the passive sampling device. Test atmospheres of HCHO were generated by decomposing trioxane vapor over an acid catalyst. Observed air concentrations agreed within 3% to those predicted by theory. The generation system was used to produce a range of HCHO concentrations between 0.05 and 2.00 ppM.