NIOSH Manual of Analytical Methods-Part I NIOSH Monitoring Methods.
NIOSH 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;
NIOSH, Public Health Service, U.S. Department of H.E.W., Cincinnati, Ohio