功能化奈米材料於微量元素分析方法開發之研究

藉由不同技術及儀器的結合，微量元素分析技術已有相當穩定且成熟的發展。然而，由於選擇性、靈敏度、儀器成本與分析時間等的限制，可即時檢測微量元素的方法被進一步探討與發展。近年在綠色化學的提倡下，兼具環保概念與分析效能的分析技術有長足的進步與發展。奈米材料因其具獨特的光學、鍵結位置多與可多樣性修飾等特性，在微量元素分析方面的應用上被大量探討。本研究主要利用兩種不同功能化的奈米材料進行微量元素分析方法之開發。首先，以表面功能化之磁性金奈米粒子作為磁性固相萃取的材料進行目標元素的前濃縮，再利用感應耦合電漿質譜儀進行水溶液樣品中汞離子之分析檢測；此方法與傳統的固相萃取法相比，無需元素脫附的步驟，因此具有步驟簡單與分析時間短的優勢。再者，藉由特定元素物種與功能化奈米基團反應聚集後之顏色變化，本研究利用穀胱甘肽進行金奈米粒子表面功能化修飾，用以進行鉻物種分析研究。研究中主要針對所發展分析方法的各實驗參數最適化條件進行探討，包括材料合成反應條件、元素吸附pH值、吸附時間/容積以及干擾因子等。在方法驗證方面，藉由inter-assay與intra-assay評估所開發方法的精密度可達RSD < 10%。本研究所開發的兩種分析方法雖尚未應用於真實樣品上，但依據研究成果顯示皆具有妥適之分析效能，與現行常用的HPLC-ICP-MS系統相較之下，簡要的前處理步驟與較短的分析時間，凸顯本方法具有建置成本低與樣品試劑需求量低的特點，在未來仍有其持續發展的潛力。

關鍵字

功能化奈米材料；磁性金奈米粒子；感應耦合電漿質譜法；分光光度法；汞；鉻物種

並列摘要

Analytical techniques for trace element analysis have been well developed based on the combination of various techniques and instruments. However, some limitations resulted from the selectivity, sensitivity, instrumental cost and analytical time have further improved the development of real-time methodology for trace elements. Based on the special optical characteristics, several nanomaterials have been used to separate and preconcentrate trace element species prior to detection through mass spectrometry or optical spectroscopy. The aim of the study was to develop two approaches for the determination of trace elements using two functionalized nanomaterials. Firstly we developed an eco-friendly, and highly selective method using a L-cysteine-coated magnetic gold nanoparticles (MNP@AuNPs) coupled with inductively coupled plasma mass spectrometry (ICP-MS) to separate trace Hg2+ ions from aqueous samples. The proposed method is simple and does not need desorption process when compared to the conventional solid phase extraction method. In addition, a selective colorimetric Cr(III) detection method was developed by using glutathione (GSH) functionalized gold nanoparticles (GSH@AuNPs). The presence of Cr(III) induced aggregation of GSH@AuNPs, yielding a color change from red to blue. To optimize the analytical characteristics of the two methods developed, we investigated several factors including reaction conditions of nanomaterial, adsorption pH, adsorption time/capability, coexisting ions and so on. The precision of the proposed two method is acceptable based on the results of inter-and intra-assay. Future studies are necessary to apply the proposed methods for analysis of real samples. In summary, the proposed two methods have some advantages including simple sample pretreatment and less reagent consumption, which have potentials for trace element analysis.

並列關鍵字

functionalized nanomaterial ； magnetic gold nanoparticle ； inductively coupled plasma mass spectrometry ； spectrophotometry ； mercury ； chromium species