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NIOSH Manual of Analytical Methods-Part I NIOSH Monitoring Methods.
Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, 1977 Apr; 1:141-142
The NIOSH analytical method for determining toluene-diisocyanate (26471625) (TDI) in air is described. TDI is hydrolyzed to the corresponding toluenediamine derivative which is then diazotized by a sodium-nitrite and sodium-bromide solution. The diazo compound is reacted with N-(1-naphthyl)-ethylenediamine to form a color complex that is analyzed colormetrically at 550 nanometers. The analytical range of the method is 0.007 to 0.14 parts per million. Free aromatic amines will interfere with the analysis.
Air-contamination; Air-sampling; Isocyanates; Analytical-methods; Diazo-compounds; Colorimetry;
DHEW (NIOSH) Publication No. 77-157
National Institute for Occupational Safety and Health
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division