| Abstract: | Abstract A practical and correct methodology for evaluating CH2O in air without sampling artifact formation is presented. Formaldehyde is collected on an annular denuder coated with bisulfite-triethanolamine. The sorbent layer is extracted with water and the solution analyzed by the chromotropic acid (CTA) procedure. Sorption efficiency and loading capacity have been investigated along with storage stability. Results of laboratory validation studies have indicated that a small annular denuder was able to sample about 300 μg CH2O without an appreciable decrease in the initial collection efficiency (99% at 2.5 1 min?1). Tests on storage stability before and after exposure have also demonstrated that both oxidation of bisulfite and release of CH2O did not occur for time periods as long as 1 month. |
