Dahlin Jakob, Spanne Mårten, Dalene Marianne, Karlsson Daniel, Skarping Gunnar
Work Environment Chemistry, Stockholm University, PO Box 460, S-281 24 Hässleholm, Sweden.
Ann Occup Hyg. 2008 Jul;52(5):375-83. doi: 10.1093/annhyg/men018. Epub 2008 Apr 30.
A new type of isocyanate sampler has been used to investigate aging aerosols generated during thermal degradation of polyurethane (PUR). The sampler consists of a denuder connected in series with a three-stage cascade impactor and a filter. The denuder collects gas-phase isocyanates. The three impactor stages had cut-off diameters (d(50)) of 2.5, 1.0 and 0.5 mum, respectively. The end filter collects particles <0.5 mum. For derivatization of isocyanates in the sampler, di-n-butylamine mixed with an equimolar amount of acetic acid was used for impregnation of the sampler stages. Consecutive sampling using three denuder-impactor samplers was performed in a test chamber, with a total sampling time of 9 min. Analysis of air samples was performed using liquid chromatography-mass spectrometry (LC-MS)/MS. Particle size measurements were performed using a scanning mobility particle sizer (SMPS). A time-dependent behavior was observed for aromatic diisocyanates during aging of the aerosol. Thermal degradation of different PUR materials showed different distribution of isocyanates between gas and particles. Aromatic diisocyanates (toluene diisocyanate (TDI) and methylene diphenyl diisocyanate) were initially in gas phase and associated to very small particles. After a few minutes most of these isocyanates were associated with particles <1 mum. Monoisocyanates and hexamethylene diisocyanate (HDI) were not found to be associated with particles.
一种新型异氰酸酯采样器已被用于研究聚氨酯（PUR）热降解过程中产生的老化气溶胶。该采样器由一个与三级串联撞击器和一个过滤器相连的去溶器组成。去溶器收集气相异氰酸酯。三个撞击器阶段的截止直径（d(50)）分别为2.5、1.0和0.5微米。末端过滤器收集小于0.5微米的颗粒。为了对采样器中的异氰酸酯进行衍生化，将二正丁胺与等摩尔量的乙酸混合用于浸渍采样器各阶段。在测试室中使用三个去溶器 - 撞击器采样器进行连续采样，总采样时间为9分钟。使用液相色谱 - 质谱联用仪（LC - MS）/ MS对空气样品进行分析。使用扫描迁移率粒径分析仪（SMPS）进行粒径测量。在气溶胶老化过程中观察到芳香族二异氰酸酯的时间依赖性行为。不同PUR材料的热降解显示出异氰酸酯在气相和颗粒之间的不同分布。芳香族二异氰酸酯（甲苯二异氰酸酯（TDI）和二苯基甲烷二异氰酸酯）最初处于气相并与非常小的颗粒相关联。几分钟后，这些异氰酸酯中的大多数与小于1微米的颗粒相关联。未发现单异氰酸酯和六亚甲基二异氰酸酯（HDI）与颗粒相关联。
