Abstract
An existing modified (no mercury reagent) pararosaniline method for the determination of formaldehyde in air has been adapted for continuous monitoring using a CEA Instruments, Inc. Model 555 automated wet chemical analyzer. The adapted instrument was checked for linearity of response, formaldehyde collection efficiency, and drift. The instrument response was highly linear (r = 0.9996) in the 1–10 ppm formaldehyde concentration range tested. Formaldehyde collection efficiency of the analyzer increased from 64 to 88% as sample flow rate was increased from 0.25 to 1.0 Lpm. When the analyzer was connected to a constant 4.1 ppm formaldehyde permeation tube source, with careful control of ambient temperature and sample cell liquid levels, 3% instrument drift occurred over a 7 hour period.