建立HPLC-UV/nano-TiO2-ICP-MS連線系統進行尿液中汞物種之分析研究

Development of HPLC-UV/nano-TiO2-ICP-MS hyphenated system for the determination of mercury species in urine sample

陳寬孺

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(2006年)

摘要

在自然環境中汞大多是經由人類行為活動產生，雖然其在自然環境的濃度極低，但仍會經由生物濃縮及生物放大的效應，在生物體內累積。不同的汞物種對人體的健康效應有非常明顯的差異，因此有效地測定出生物檢體中汞物種的濃度分布情形，一直是分析化學領域中亟欲解決的熱門課題之一。
在目前常見的汞物種連線分析技術中，多數是使用冷蒸氣生成裝置作為串聯層析系統與偵測器之介面，但此類利用化學試劑氣化汞離子的方法，由於所使用的強還原試劑，大都是對環境不友善之化合物，因此，本研究中乃利用nano-TiO2特殊之光催化特性，嘗試建立一套UV/nano-TiO2光還原裝置，作為層析系統與ICP-MS間的介面，除了可以避免使用強還原試劑，還可以達到比傳統方法更低的偵測極限。實驗結果顯示，對本研究欲測定之二個汞物種Hg2+及MeHg+而言，可達到的偵測極限分別為0.10及0.03 μg/L，每次測定所需的時間為15分鐘，分析結果的精密度（RSD%值）則均可維持在10 %以內。在確認利用所建立之連線分析系統（HPLC-UV/nano-TiO2 -ICPMS）進行尿液中汞物種測定可行性的過程中，本研究係利用標準尿液參考樣品及添加樣品的分析結果進行評估，實驗結果顯示，本研究所開發之連線分析系統確實可快速且準確地測得各汞物種的濃度，而且根據本研究所建立之連線分析技術，亦可實際測得尿液樣品中二價汞物種的濃度。

關鍵字

汞 ； 物種分析 ； 光催化

並列摘要

Abstract
With elemental, inorganic and organometallic mercury each having different chemical and physical properties, routes of exposure, and toxicological effects. The analysis of mercury species has proven to be critical in assessing their direct influence on the environment, predicting their transport behavior in several ecosystem compartments and in the decontamination of hazardous pollutant materials. Although considerable efforts have been made in recent years for mercury speciation analysis, the analytical methodology still needs further improvement to promote the analytical sensitivity of detection.
In order to meet the request for investigating biological significance of mercury species, in this study, Hg2+ and CH3Hg+ were separated using a cation-exchange chromatography column packed with polyhydroxy methacrylate gel. After the chromatographic separation, on-line transformation of mercury species into gaseous products by UV/nano-TiO2 photocatalysis reduction device was investigated to enhance the sensitivity of detection and reduce the non-spectral interference resulted from sample matrix. In order to enhance the vaporization efficiency, the effects of acidity, amount of TiO2 and formic acid on the vaporization efficiency of Hg2+ and CH3Hg+ were investigated. Based on the experimental results, 100 mM formic acid and 3 g/L nano-TiO2 suspension (Degussa p25) were used to on-line vaporize two mercury species under UV illumination. With our proposed procedure, Hg2+ and CH3Hg+ in the column effluent can be on-line vaporized and determined by ICP-MS after the chromatographic separation without the need of conventional chemical vaporization method.

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