Development of Air-Monitoring Techniques Using Solid Sorbents. LASL Project R-059, Niosh-Ia-75-31. Progress Report, April 1, 1975--September 30, 1975

摘要

Work toward the specification of methods for air sampling and analysis of four groups of organic compounds has continued. These four groups are (1) low-boiling aliphatic amines, (2) low-boiling hydrazines, (3) pyridines, and (4) formaldehyde. The methods involve collection of vapors on a solid sorbent in a tube through which air is drawn. Retention of n-butylamine, pyridine, and 1,1-dimethylhydrazine has been measured for several sorbents. The most effective is sulfuric acid-coated silica gel. A second step in each method is the removal of the sample from the selected sorbent by elution with a solvent. Desorptions of seven aliphatic amines from silica gel, of pyridine from porous polymers and sulfuric acid-coated silica gel, and of formaldehyde from alumina have been studied. A gas chromatographic method was developed for pyridine and 2-amino-pyridine analysis. Storage of formaldehyde collected on alumina was measured. The rapid loss observed limits the sampling period to 30 min and requires immediate elution. Alumina tubes and bubblers were compared for sampling formaldehyde vapors in air.