Abstract
本研究以發展環境及生物樣品中超微量元素的分析為目標。首先 探求適當的樣品前處理方法，將可能形成干擾的物質去除，再配合儀器的 最佳操作條件，進行樣品中微量及超微量元素的測定。 研究的內容包括 三個主要的部份。第一部份係以建立地下水中稀土元素的超微量分析為主 題。水樣經調整至 pH 8.5 - 9.0 後，利用奎林酚固著矽膠以單槽批次方 式，將稀土元素自大量水樣(500 ml-1000 ml)中螯合吸附，再以稀酸溶液 溶洗，繼利用高靈敏的感應耦合電漿-質譜儀(ICP-MS)作偵測。結果顯示 ，本方法所得的空白值可有效地被控制，對稀土元素的偵測極限均可低達 ppt 程度。以此方法應用於烏腳病地區及一般地區地下水的分析，結果並 未發現地下水中稀土元素含量的高低與烏腳病間有相關性存在。第二部份 以開發線上(on-line)濃縮測定技術應用於地下水樣中稀土元素的分析為 重點。首先探求奎林酚固著矽膠管柱對稀土元素的吸附與脫附的特性，繼 探求管柱與ICP-MS連線的最適操作條件。由所得結果顯示，此連線分析系 統除了可達到快速分析及低樣品需求量的特點外，更可大幅提昇分析的靈 敏度，估計其偵測極限值約可比前者低5倍以上。第三部份則以尿液樣品 中超微量鎘分析技術的建立為目標。尿液中有機物先利用微波消化予以破 壞後，殘存的鹽類基質再以自行設計的奎林酚固著矽膠管柱予以分離。經 處理後所得的樣品溶液，由於基質已大幅簡化，故可利用電熱式原子吸收 光譜儀(ETAAS)逕以快速的昇溫程式作待測物的測定。結果顯示，所建立 的前濃縮方法配合簡化的光譜測定技術可有效的提高分析效率，滿足生物 樣品中超微量元素分析的需求。綜合以上的結果顯示，本研究所建立的樣 品前處理技術，可有效的控制分析空白值，去除干擾基質；經前處理所得 的樣品配合高靈敏儀器(ICP-MS及ETAAS)的測定，證實確能達到超微量元 素的準確分析目標。 This study is aimed to develop an analytical techniqueconsisting of preconcentration and optical and mass spectrometryfor the determination of ultra-trace amounts of elements in the environmental and biological samples. There are three main topics included in this work. Firstly, a method for the determination of ultra-trace levels of rare earth elements (REEs) in the groundwater via batch preconcentration method followed by the measurement with inductively coupled plasma - mass spectrometry (ICP-MS) was developed. Silica-immobilized 8-hydroxyquinoline (I-8HOQ) was used as adsorption material for preconcentration of REEs from water sample and the analytes eluted was determined by ICP-MS. The detection limits for the respective REEs obtained can be amounted to as low as ppt or sub-ppt levels. The method established was applied to the determination of REEs in the artesian well water of the blackfoot disease endemic area in Taiwan. In the subsequent part, further advancement of preconcentration of REEs by an on- line column process followed by ICP-MS measurement was developed. With this on-line analytical system, the detection limits achievable for REEs can be about one order lower than that of the batch preconeentration method. The main features of this on-linemethod lie in its high sensitivity, smaller sample required for analysis and rapid sample throughput. Various important factors influencing the preconcentration efficiency of the column such as pH, flow rate and coexisting ions were investigated. Finally, a method was proposed for the determinationof cadmium in the microwave digested urine sample based on I-8HOQseparation followed by detection with electrothermal atomic absorption spectrometry (ETAAS). With this method, the determination of cadmium in urine could be completely freed from the matrix interferences. Neither ashing steps in the furnace heating program nor use of matrix modifiers was necessary.With meticulous control of systematic errors the limit of detection for Cd in urine sample can be as low as 0.04 μg/L.The method presented can serve as a reference technique for theanalysis of cadmium in urine samples.