多孔材料應用於空氣中揮發性污染物的萃取

Mesoporous Silica Used in the Enrichment of Ambient Organic Pollutants

吳東明(Tung-Min Wu) ； 高憲明(Hsien- Ming Kao) ； 王家麟(Jia-Lin Wang)

《化學》 63卷3期 (2005/09) Pp. 353-364

https://doi.org/10.6623/chem.2005029

摘要

空氣中的氣態有機物質雖是造成空氣品質劣化的主因之一，但大部分物質濃度往往並不及於儀器之偵測下限而無法直接鑑定，因此濃縮成為必要的手段。現今濃縮技術結合氣相層析儀已成為分析氣態有機污染物的最佳方法。選擇微孔徑(＜20Å)碳分子篩作為濃縮介質再以熱脫附方式送入氣相層析儀分析已成為現今接受度很高的標準方法，然而使用者對於商業化微孔碳分子篩的選擇有限，再加上專利原因與熱穩定性不夠等因業限制了分析效果的提升，因此本文在此除了介紹線上濃縮與分析的概念外，並介紹一種新吸附性材料中孔極矽分子篩用於有機污染物的線上濃縮。由於其孔徑明顯大於商業化的微孔徑碳分子篩，因此在吸附分子的選擇性上出現差異，脫附溫度也遠低於以往的碳分子篩，有利於氣相層析儀的快速注入與拖尾的改善，並預期其較大的孔徑也將能往上擴大其吸附分子量範圍。

關鍵字

微孔碳分子篩 ； 中孔徑矽分子篩 ； 線上濃縮

並列摘要

The ubiquitous presence of anthropogenic organic pollutants has induced a variety of environmental concerns ranging from ozone depletion over the Antarctic, enhanced global warming, surface ozone pollution, etc. Nevertheless , the abundance of these pollutants is often below the detection limits of modem analytical instruments. Enrichment methods coupled with GC techniques have shown sufficient sensitivity to measure volatile organic compounds (VOCs) and consequently have been widely accepted as standard methods for VOC measurement. Although , the employment of carbon molecular sieves for on-line or off-line trapping organic pollutants is popular, the propriety and the limited selection of these commercially available sorbents have hindered their wider applications. As a result, a new class of molecular sieve, i.e., mesoporous silica molecular sieves has been synthesized and studied for their relationship between porosity and size selectivity for the enrichment of VOCs by supplying an array of VOC target compounds with molecular size ranging from C_2-C_(12) analyzed by a self-designed auto-GC system.

並列關鍵字

Microporous carbon molecular sieves ； mesoporous silica molecular sieves ； in-line enrichment