使用高空間及高時間解析方法應用於小分子之分析

Abstract

在分析化學領域中，發展出具高空間及高時間解析分析方法已成為日益重要的課題，例如在基質輔助雷射脫附游離質譜影像分析中，提升空間解析有助於將質譜影像到達微米等級的解析度；而提高時間解析也有利於各種化學動力學之即時偵測與探討。 在本論文中，首先我們發展出一種能應用在基質輔助雷射脫附游離質譜影像分析的有機無機混合材料奈米粒子。此奈米粒子為含有基質輔助雷射脫附游離質譜基質的矽球，其表面帶有正電荷，能藉由靜電吸引力吸附在帶有負電荷的生物樣品(藻類)上，接著在使用氨水蒸汽將奈米粒子中基質輔助雷射脫附游離質譜的基質釋放出來。使用本論文開發出的奈米粒子配合光徑10 μm的紫外光雷射對樣品進行脫附游離，在基質輔助雷射脫附游離質譜影像分析能達到15 μm左右的高空間解析度質譜影像結果。 在本論文的第二部份，我們自行組裝出一種能同時進行多點和多探測光源偵測的光學儀器；利用此光學儀器結合間隔式和連續式進樣法，我們成功達成監控分析物在溶液中對流情形的線上即時偵測。此外，本論文開發的光學儀器可與電噴灑游離法離子阱質譜儀進行串聯，接著配合連續式進樣法進樣來監測分析物對流情形，我們也成功的同時利用本論文所裝設的系統得到吸收光譜和質量分析的線上即時偵測結果。相信本論文開發出的實驗方法在未來能對自然界很多物理現象的討探會有很好的貢獻。

Development of analytical methods with high spatial resolution and high temporal resolution has become an important goal in analytical chemistry. For example, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) enables mapping chemical molecules in two-dimensional samples with a micrometer-range spatial resolution. On the other hand, fast detection techniques are introduced to accommodate the analysis of dynamic chemical systems. In this work, we demonstrate hybrid nanoparticles which can facilitate mass spectrometric imaging at high spatial resolution. The nanoparticles attach to biological specimens (algal cells) due to electrostatic interactions, which is further followed by a controlled release of an organic MALDI matrix in the presence of alkaline vapors of ammonia. Using this method – in conjunction with a MALDI-MS instrument equipped with a 10-µm ultraviolet laser beam – we achieved the spatial resolution of approximately 15 μm. In the second part – in order to preserve temporal resolution – we implemented an on-line sampling system which takes advantage of segmented or continuous flow. The system was used in conjunction with a home-made multi-point multi-wavelength optical detector. The device enabled real-time monitoring of convection currents. The continuous flow sampling, and the optical detector, were readily hyphenated with an electrospray ion-trap mass spectrometer. This enabled online analysis of the low-volume liquid samples collected from the convection vessel – simultaneously – by light absorption and mass spectrometry. We believe that the developments presented here will contribute to new discoveries in natural and physical sciences.