Determination of Elements in Blood by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

利用雷射剝蝕結合感應耦合電漿質譜儀分析血液樣品中的無機元素

張瑋珊(Wei-Shan Chang)

指導教授 ： 王竹方

國立清華大學/原子科學院/生醫工程與環境科學系/碩士(2008年)

https://doi.org/10.6843/NTHU.2008.00225

摘要

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been applied to elemental determination in blood samples. Determination of the elemental concentrations in human body fluid is important recently, since the unusual concentrations of elements imply the information in health. It is well known that children are especially sensitive to the toxic effects of lead (especially under the age of 5), since compared with adults, a greater proportion of systemically circulating lead reaches the brain, and results in damage of the vulnerably developing nervous system. In this study, we try to determine elements in blood using LA-ICP-MS. Several parameters including sample preparation (spot size and dilution method) and laser system (laser energy, defocus distance, dwell time and intersite pause) were studied.
Solution nebulization is the usual sample introduction method for elemental analysis by ICP-MS, but the use of the direct laser ablation of solids has grown very rapidly. LA-ICP-MS is a novel method for the determination of elements in blood. 0.5 μL of blood samples were deposited onto a hydrophobic PTFE filter, which was then placed under atmosphere and dried. Little pretreatment is needed, so that an introduction of contamination through sample pretreatment can be avoided. In order to ablate the blood spots completely with the PTFE filter intact, a parameter of 2 mm defocus distance was selected to maximize the width of the laser beam and produce a relatively large stable signal. Although the LA-ICP-MS has many advantages, quantitative analysis remains problematic due to the lack of matrix-matched solid standards for calibration. In addition to the development of micro-droplet standard solution calibration, dilution of high concentration blood standard reference material and multi-element standard solution were used.

關鍵字

雷射剝蝕 ； 感應耦合電漿質譜儀 ； 血液

並列摘要

雷射剝蝕結合感應耦合電漿質譜儀（laser ablation inductively coupled plasma mass spectrometry，LA-ICP-MS）已經被應用在分析血液內的元素。分析人類體液中的元素在最近受到重視，有些研究指出元素濃度含量的異常透露出身體健康的訊息。相較於成人，小孩子對於鉛所造成的影響更為敏感是眾所皆知的（特別在五歲以下），在體內循環的鉛大部分會到達腦部，破壞小孩子正在發育的神經系統。本研究藉由LA-ICP-MS建立分析無機元素技術，用以分析血液內元素含量，並探討相關實驗參數的影響包括：樣品前處理（液滴大小、稀釋方式）和雷射系統（雷射能量laser energy, 離焦距離defocus distance, 停留時間dwell time, 區間暫停時間intersite pause）等。
利用ICP-MS分析元素最廣泛使用的進樣方式為液體霧化器進樣（solution nebulization），但是利用雷射剝蝕固體進樣方式也發展的相當快速。對於分析血液內的元素來說，利用LA-ICP-MS分析是一個新穎的方法，本研究僅利用0.5?L的血液樣品滴在疏水性鐵弗龍濾紙上，置於室溫下自然乾燥，隨後即可以LA-ICP-MS進行元素含量分析。不需要複雜的前處理程序，可以避免血液樣品在前處理過程中受污染，並可縮短樣品分析時間。為了將乾燥在濾紙上的液滴剝蝕完全並維持濾紙的完整無缺，離焦距離固定於2 mm，在此條件下有較大的剝蝕面積與強而穩定的離子訊號。即使LA-ICP-MS具有許多優點，但因為基質匹配的標準品不易取得而使其在定量分析上遭遇困難；本研究探討以血液參考標準品與多元素標準溶液製備檢量線，分析血中元素含量的可行性，並以血液參考標準品進行回收率測試，研究結果顯示兩者皆可達到定量分析的目的。

並列關鍵字

Laser ablation ； inductively coupled plasma mass spectrometry ； blood

參考文獻

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