以微層析晶片建構二維氣相層析方法之研究

Abstract

本研究藉由微機電製程技術(micro electro mechanical system, MEMS)製作微層析晶片(μ-column)，並在微層析晶片內塗佈DB-1以及DB-210兩種不同靜相材料。利用靜相材料對揮發性有機氣體(VOCs)不同的滯留效果，設計出三種不同架構的二維氣相層析儀(2D-GC)，來解決單一微層析晶片分離效果不足的問題。 市面上裝置於2D-GC內的調節器有冷卻式和機械式兩種，然而冷卻式調節系統需要液態氮或二氧化碳鋼瓶，這與微型氣相層析儀(μGC)特有的可攜性相違背，因此微型氣相層析儀不適合使用冷卻式調節器。 本研究的三種調節系統分別是Heart cutting GC × GC系統、Deans switch GC - GC系統、以及Stop-flow GC - GC系統。其中Heart cutting GC × GC系統和Stop-flow GC - GC系統都可以在五分鐘內分離出11種沸點相近的有機混合氣體，雖然Heart cutting GC × GC系統因分流而造成樣品的損失，但也因此得到較佳的分離效果。Deans switch GC - GC系統可連接兩組偵測器，增加實驗的效率，以同樣的混合氣體來說，此系統只需要一半的時間即可完成這些氣體的分離。Stop-flow GC - GC 系統對硬體的需求最輕微，但是實驗所需的時間是在這三種系統中最長的。 The goal of this research is to investigate three different configurations of two dimensional gas chromatography (2D-GC) when using two of micro electromechanical system (MEMS) technology fabricated -column chips coated with DB-1 and DB-210 as stationary phases. Taking advantage of dissimilar retentions for VOCs of the two stationary phases and 2D-GC, we resolve the problem of insufficient separation using single, short -column chip. Commercial modulators for 2D-GC are cryogenic or valve-based. However, cryogenic modulators need to have cylinders of liquid nitrogen or carbon dioxide. It violates the unique purpose of portability for μGC. Hence, μGC should use only cryogenic free modulators. The three modulator systems for 2D-GC investigated in current study are Heart cutting GC × GC system, Deans switch GC - GC system, and Stop-flow GC - GC system. The Heart cutting GC × GC system and Stop-flow GC - GC system can separate eleven VOCs of similar boiling points within five minutes. Although the Heart cutting GC × GC system causes the loss of sample mass due to splitting, it achieves better separations. The Deans switch GC - GC system links to two detectors so that it increases the efficiency of experiment. Comparing with the same VOCs, this system only takes a half of time to finish the separation of these. Stop-flow GC - GC system is the lightest in hardware requirements, but it is also the most time consuming among three modulator systems.