三層濾紙TDI蒸氣與氣膠同步個人採樣器

Simultaneous Personal Sampling of Vapor and Aerosol TDI with a Triple Filter System

目前關於二異氰酸甲苯(TDI)的氣相及氣膠相分離採樣技術，有雙濾紙採樣方法及環形固氣分離採樣法兩種，前者採樣問題為前置鐵氟龍濾紙會吸附 TDI 蒸氣導致氣膠相之濃度可能會被高估；後者採樣問題為體積過於龐大，不適合作個人採樣之用，雖然雙濾紙採樣方法已有模式可以估計鐵氟龍濾紙氣體吸附量，但模式的建立與計算過程卻相當繁複。針對上述問題，本研究研發出一個新型三層濾紙氣膠及氣體分離採樣器，並藉由簡易模式的推估可以克服雙濾紙採樣方法中前置鐵氟龍濾紙吸附二異氰酸甲苯氣體導致氣膠相之濃度被高估而氣體的濃度被低估的問題。整個三層濾紙採樣系統為上層鐵氟龍濾紙、中置鐵氟龍濾紙與下層玻璃纖維濾紙的組合。經由雙層鐵氟龍濾紙的氣體吸附測試，發現當兩片鐵氟龍濾紙串聯採樣時，兩者的吸附效率非常相近；另外在 TDI 氣膠揮發試驗中得知鐵氟龍濾紙所收集的氣膠，揮發量微乎其微。由於這兩個發現，只要知道這三片濾紙的 TDI 採樣量並藉由模式的運算，就可以很正確的推估出環境中氣膠與蒸氣的濃度。

There are two methods currently in use to separate gas toluene diisocyanate (TDI) from its aerosol counterpart. One is the dual filter system and the other is the annular denuder method. The former has the problem that the Teflon filter adsorbs gaseous TDI resulting in overestimation of aerosol TDI concentration. The latter is usually bulky in size making it unsuitable as a personal sampler. To overcome these problems, a new triple filter system consisting of two Teflon filters followed by a glass fiber filter has been invented. The system allows us to estimate TDI vapor adsorbed by the 1st Teflon filter hence the exact amount of vapor- and aerosol-phase TDI can be determined. According to the gas adsorption tests of two Teflon filters in series, the TDI vapor collection efficiency of two Teflon filters is almost the same. The results of the vaporization test using pure TDI aerosol show that it barely vaporizes during sampling. These two findings allow us to use a simplified model to estimate accurate aerosol- and vapor-phase TDI concentrations.