A chemosorptive cylindrical denuder designed for personal exposure measurements of isocyanates-evaluation on generated aerosols of 4,4'-methylenediphenyl diisocyanate.
A denuder/filter system constructed for solvent-free personal exposure measurements was evaluated for separation of vapour and particulate 4,4'-methylenediphenyl diisocyanate (4,4'-MDI) generated from heated PUR-foam. The two different phases were collected in the denuder and on the filter, respectively, by chemosorption on a polydimethylsiloxane (SE-30)-dibutylamine (DBA) stationary phase. Both repeatability and the total mass concentration of 4,4'-MDI were similar to that obtained from the reference method, in this case an impinger/filter system. The penetration of particles through the denuder at 300 ml min(-1) was nearly 100% in the particle size range 25 to 700 nm, which fits well with the Gormley-Kennedy equation. Denuder/filter sampling of the 4,4'-MDI aerosol at 500 ml min(-1) yielded a phase distribution that was in accordance with the results from the reference method. The method limit of detection was 6 ng m(-3) and 4 ng m(-3) for the denuder and filter, respectively, when using an air sampling flow rate of 300 ml min(-1) and a sampling period of 15 min. This is well below the Swedish occupational exposure limit (OEL) of 50 and 100 microg m(-3) for an 8-hour working day and a 5-min period, respectively.
Nordqvist
Yvonne
Y
Department of Analytical Chemistry, Stockholm University, S-106 91 Stockholm, Sweden.
Nilsson
Ulrika
U
Colmsjo
Anders
A
Dahl
Andreas
A
Gudmundsson
Anders
A
D000327:Adsorption; D000336:Aerosols; D000485:Allergens; D004784:Environmental Monitoring / Q000295:instrumentation*; D005374:Filtration; D006801:Humans; D017953:Isocyanates / Q000032:analysis*; D016273:Occupational Exposure; D010316:Particle Size; D012016:Reference Values; D012680:Sensitivity and Specificity; D014835:Volatilization; D001559:Benzhydryl Compounds
D000336:Aerosols; D000485:Allergens; D017953:Isocyanates; C005969:4,4'-diphenylmethane diisocyanate; D001559:Benzhydryl Compounds