NIOSH 1974 Jan:125-125
A method is described for the spectrophotometric determination of formaldehyde in the air. Formaldehyde reacts with chromotropic-acid (148254) and sulfuric-acid (7664939) solution to form a purple monocationic chromogen. The absorbance of the colored solution is read in a spectrophotometer at 580 nanometers and is proportional to the quantity of formaldehyde (50000) in the solution. Details are given as to interferences, range and sensitivity, precision and accuracy, effect of storage, instrumentation and sampling equipment, reagents, collection and shipping of samples, calibration and standards, and calculations.
Analytical-Methods; Toxic-substances; Air-quality-measurement; Air-sampling; Sampling-methods; Colorimetry; Analytical-instrumentation; Formaldehyde; Aldehydes; Microanalysis;
148-25-4; 7664-93-9; 50-00-0;
Division of Laboratories and Criteria Development, NIOSH, Cincinnati, Ohio, NIOSH Manual of Analytical Methods, HEW Publication No. (NIOSH) 75-121