The measuring and monitoring of formaldehyde in inhalation test atmospheres.
The formaldehyde levels in the exposure chambers used for a six-month inhalation study were measured by collecting impinger samples which were analyzed by the chromotropic acid colorimetric method. The levels were also monitored continuously by CEA 555 air monitors. In developing a joint laboratory analytical program, one version of the chromotropic acid procedure was found to give erroneous results. Difficulties were also experienced due to sample contamination during shipment. It was shown that dilute formaldehyde solutions in 1% sodium bisulfite were much more stable than aqueous solutions. Adoption of satisfactory sample shipment methods and standarization of the analytical procedure produced good agreement in the results obtained for impinger samples analyzed by both laboratories.
D000388:Air / Q000032:analysis; D001273:Atmosphere Exposure Chambers; D055598:Chemical Phenomena; D002621:Chemistry; D003124:Colorimetry / Q000379:methods; D005557:Formaldehyde / Q000032:analysis*; D013997:Time Factors
D005557:Formaldehyde