建立開管式固相萃取晶片搭配感應耦合電漿質譜儀之連線分析系統進行高鹽基質微透析樣品中微量元素之分析研究

Development of Chip-Based Open Channel Solid Phase Extraction Coupled to ICP-MS for On-Line Determination of Trace Elements in Microdialysates

陳威宇(Wei-Yu Chen)

指導教授 ： 孫毓璋

國立清華大學/原子科學院/生醫工程與環境科學系/碩士(2009年)

摘要

隨著生物醫學快速發展的時代，目前已有許多文獻證實微量元素在生物體中確實扮演著極為重要的角色，當生物體內金屬離子濃度有些許變化時，即可能會引發不同的疾病；然而，大多傳統的分析方法，僅能提供整體混合樣品（Bulk）的分析結果，無法了解微量元素在生物體內特定區域之即時、動態的分佈濃度資訊，這對於從事生醫研究人員或是現代的分析化學家而言，均是亟須突破的技術瓶頸。探究造成此技術瓶頸的原因，主要係源於分析物濃度過低和樣品基質過於複雜，及自生物體取得之樣品體積通常均極少（5~10 μl）有關。有鑒於此，本研究的目的係將固相萃取概念導入流控晶片技術中（Fluidics），藉此開發出一套高靈敏、低汙染、操作簡單且可用於量樣品的分析方法。
一般而言，在進行連續進行動態監測活體動物體內特定器官中微量元素時，有效地分離透析液中的鹽類基質與控制汙染的發生，是突破在小量樣品中分析微量元素的關鍵技術。為達上述分析的目的，本研究已成功地針對(1)樣品體積受限，(2) 低分析空白值，(3)分析速度快，及(4)有效濃縮分離待分析元素等需求，建立了一套Microdialysis-Chip-Based Open-Channel SPE-ICP-MS連線分析系統。
根據各項最佳化操作條件參數，在分離過程中，本研究係將樣品的pH值調控在pH值為9，當樣品流經活化處理過之PMMA晶片時，即可藉由流道壁上之羧酸根（Carboxylate，COO-）與待分析之微量元素間的作用，達到濃縮分離的目的；在流洗過程中，本研究係利用0.5%（v/v）HNO3將吸附於流道壁上的分析物流洗下來後，再導入ICP-MS中進行測定。整個實驗流程係透過自動化控制系統進行操控，每次分析流程可控制於7分鐘內完成。本研究所建立之Chip-Based Open-Channel SPE-ICP-MS搭配微透析取樣技術（Microdiallysis sampling）使用時，在每次取樣體積為10 μl（每次測定時間為12分30秒）的條件下，確實可同時進行多種微量元素的測定，據此可知，本研究所開發Microdialysis-Chip-Based Open-Channel SPE-ICP-MS連線分析系統，確實具有長時間在急性、慢性、麻醉或清醒動物的取樣模式下，進行活體動物體內微量元素連續（Continuous）、即時（Real time）之動態監測的潛力。

關鍵字

感應耦合電漿質譜儀 ； 固相萃取晶片

並列摘要

Abstract
Nowadays, inductively coupled plasma mass spectrometry (ICP-MS) has become one of the most powerful trace elemental analytical techniques with high sensitivity as well as wide linear dynamic range and simultaneous multielement detection capability. However, the insufficient tolerance to the dissolved salts and polyatomic interferences always makes it difficult to directly analyze the high-salt content samples. Consequently, incorporating an efficient on-line pretreatment technique with ICP-MS is considered as an indispensable alternative to preconcentrate desired analytes and to minimize the adverse effects resulted from the concomitant matrices. To date, among the available on-line sample pretreatment methods, solid phase extraction (SPE) is particularly useful as a result of its simplicity and efficiency. For purpose of simplifying the analytical procedure and minimizing the volume of chemicals, in this study, a functionalized PMMA fluidic-chip as a solid phase extraction adsorbent was developed to couple with ICP-MS measurement.
Recently, Lab-on-valve mesofluidic analytical system (LOV-MFAS) is a potential tool for the analysis of the real-world micro-samples. Based on literatures, the miniaturized SPE devices indeed provide the rapid response time and analytical capability because of its high surface-to-volume ratio and the short diffusion distance. Accordingly, we attempt to exploit a proper and effective SPE material namely functionalized poly(methyl methacrylate) (f-PMMA) for the extraction of trace metal ions, and to develop a mesofluidic SPE chip to eliminate the possible salt-interference resulting from sample matrices prior to ICP-MS measurement.
In this study, a simple CO2-laser engraving technique was employed to machine PMMA substrates instead of lithographic techniques and to attain low per-unit manufacturing cost and rapid prototyping. According to our experiment, a hyphenated system of on-line Chip-Based Open-Channel SPE coupled to ICP-MS was successfully constructed for the determination of trace elements in samples of limited volume (5~10 μL). With optimized procedure, the analytical performance of proposed hyphenated system was examined for determining the concentrations of trace elements in standard reference materials (SRM 2670 and 1643e). Presently, we have connected microdialysis (MD) sampling and Chip-Based Open-Channel SPE-ICP-MS together to determine trace elements in the microdialysate samples. For purpose of establishing a physiopathological-related animal model of trace elements, the practicability of this hyphenated system was evaluated in vitro by monitoring the step change in the concentrations of analyte ions in an external microdialysis medium.

並列關鍵字

ICP-MS ； Chip

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