結合拋棄式滴管內APDC/MIBK微萃取系統與雷射剝蝕耦合電漿質譜儀分析水樣中之鉛鎘元素

Combining APDC/MIBK microextraction in a pipette with LA-ICP-MS for analyzing Pb and Cd in water samples

林孟涵(Meng-Han Lin)

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(2013年)

摘要

本文針對高基質背景的樣品溶液，使用APDC – MIBK系統微萃取，搭配雷射剝蝕結合感應耦合電漿質譜儀 ( LA -ICP-MS ) 分析，偵測鎘和鉛的訊號。本文提出的分析方法有幾個優點強調，第一：由於雷射剝蝕感應耦合電漿的可偵測小體積樣品之優點，在整個分析過程中待測水體只需4毫升體積。第二：藉由300微升APDC敖合劑與待測水體中微量金屬離子形成錯合物，具有排除鹽類與其他基質之效果，特別有利於海水樣品偵測。第三：待測樣品藉由200微升MIBK有機溶劑達到濃縮效果，有利降低偵測極限。第四：本篇實驗環境使用可拋棄式滴管，費用低廉，操作容易，且滴管的柔軟可塑性使我們更容易在實驗過程中吸取到有機層，整個萃取過程也僅需要15分鐘即可完成。第五：最後萃取過金屬離子的有積層，只需取出0.1微升體積至於基板(本文選擇透明塑膠片)上進行乾燥，就可以送入雷射剝蝕感應耦合電漿質譜儀中進行偵測，具有良好的回收率與線性。
回收率方面，從含有鎘平均濃度為每公升3.1微克和鉛每公升9.3微克的水標準樣品中 ( NIST 1640 )，得到的分析回收率分別為95 ±3 ％和104 ±4 ％。偵測極限分別為鎘每公升0.6微克的和鉛每公升0.9微克。在複雜的基質溶液中如海水，相應的檢測限分別為鎘每公升19.42微克，鉛每公升8.57微克。此外，我們也預期未來將微萃取系統更換為其他特定的螯合試劑，可能可以達到更高的選擇性。

關鍵字

拋棄式滴管 ； 微萃取系統 ； 雷射剝蝕 ； 感應耦合電漿質譜儀

並列摘要

This paper demonstrated a highly matrix-tolerant analytical method by using a combination of ammonium pyrrolidine dithiocarbamate/methyl isobutyl ketone (APDC-MIBK) microextraction and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), for Cd and Pb determination. Several advantages of proposed analytical method are emphasized herein. First, it took only 200 µL of organic solvent throughout the entire analysis process, with enhancement factors as high as 25. At the same time, recoveries from replicate analyses of natural water [NIST 1640(a)] containing mean concentrations of 3.1 μg Cd L–1 and 9.3 μg Pb L–1 were 95 ± 3 and 104 ± 4%, respectively. The corresponding detection limits were 0.6 μg L–1 for Cd and 0.9 μg L–1 for Pb. Second, it was capable of analyzing solutions containing complicated matrix such as seawater. Corresponding detection limits in seawater were 19.42 μg L–1 for Cd and 8.57 μg L–1 for Pb. Furthermore, a higher selectivity can be possible when replacing APDC with other specific chelating reagents.

並列關鍵字

APDC/MIBK ； microextraction ； LA-ICP-MS

參考文獻

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