Real-time measurement of methyl nitrite in air by nitrogen oxide indicating tubes.
Nowak-JL; Puskar-MA; Levine-SP; Xiao-HK
Appl Occup Environ Hyg 1993 Jul; 8(7):645-649
The real time measurement of methyl-nitrite (624919) (MeNO2) in air using nitrogen-oxide indicating tubes was described. Gilian HFS-513 or HTS-513A pumps calibrated to deliver 2 liters of air per minute were used to fill 5 or 10 liter Tedlar bags with known volumes of laboratory air. A scaled down reaction apparatus for the production of MeNO2 was described. The MeNO2 liberated from this apparatus was extracted in aliquots and transferred to the Tedlar bags through septum ports. A bellows type hand pump was used with nitrous fumes tubes to measure the concentration MeNO2 in each bag, with ten full pump strokes being used for standards at or below 20 parts per million (ppm) MeNO2, and five strokes for the 100ppm level. Samples from the prepared standards of MeNO2 reacted with the indicator tubes to produce a dark blue stain on the quantitative layer at 800 to 900 millimeters, and no color change was visible with clean laboratory air. The length of stain was proportional to the concentration of MeNO2 in each bag. Highest precision was at less than or equal to 10ppm MeNO2. A test to determine whether other components in the manufacturing facility caused positive interference with measurement accuracy showed no interference when MeNO2 was not being used in any process. The authors conclude that the method is suitable for measuring MeNO2 gas in air at concentrations between 2 and 100ppm.
Air-quality-monitoring; Analytical-methods; Nitrogen-compounds; Toxic-gases; Chemical-indicators; Chemical-manufacturing-industry; Gas-detectors
Environmental & Indust Health University of Michigan 1420 Washington Heights Ann Arbor, MI 48109-2029
Other Occupational Concerns; Grants-other
Applied Occupational and Environmental Hygiene
University of Michigan at Ann Arbor, Ann Arbor, Michigan