Simultaneous sampling of gas- and aerosol-phase TDI with a triple filter system.
A new triple filter system sampler/model is proposed for the precise and accurate simultaneous sampling and determination of gas- and aerosol-phase 2,4-toluene diisocyanate (TDI). The system consists of two front Teflon filters for sampling aerosol-phase TDI and a final coated glass fiber filter to collect gas-phase TDI. The aerosol-phase TDI is collected on the first Teflon filter, while the second Teflon filter is used to estimate gaseous TDI adsorbed by the first. According to the gas adsorption test of two Teflon filters in series, the TDI gas adsorption fraction of the two filters is almost the same. Results of the evaporation test using pure TDI aerosols collected on the Teflon filter show that significant evaporation of the compound does not occur during sampling. These two findings allow the use of a model to estimate accurate gas- and aerosol-phase TDI concentrations. The comparison test with an annular denuder shows that the triple filter system can minimize the TDI sampling bias between the dual filter and the annular denuder systems.
Tsai
Chuen-Jinn
CJ
Institute of Environmental Engineering, National Chiao Tung University, Hsin-chu, Taiwan. cjtsai@mail.nctu.edu.tw
Cheng
Kai-Chung
KC
Aggarwal
Shankar G
SG
Shih
Tung-Sheng
TS
Hung
I-Fu
IF
D000336:Aerosols; D004784:Environmental Monitoring / Q000379:methods*; D005374:Filtration; D005740:Gases; D012680:Sensitivity and Specificity; D014051:Toluene 2,4-Diisocyanate / Q000032:analysis* / Q000302:isolation & purification; D017132:Workplace
D000336:Aerosols; D005740:Gases; D014051:Toluene 2,4-Diisocyanate