Please use this identifier to cite or link to this item:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/83830
Title: | 微電漿光譜技術檢測水溶液中重金屬之研究 Detection of Metallic Ions in Solution Using Optical Emission Spectrometry of Microplasmas |
Authors: | 邢輔恩 Fu-En Hsing |
Advisor: | 徐振哲 Cheng-Che Hsu |
Keyword: | 微電漿,重金屬檢測,濾紙電極,毛細管電極,電漿放射光譜, microplasma,heavy metals detection,filter paper electrodes,capillary electrodes,plasma emission spectroscopy, |
Publication Year : | 2022 |
Degree: | 碩士 |
Abstract: | 微電漿具有高能量密度、體積小、可常壓操作等特性,因此本研究嘗試開發出微電漿裝置,希望能達到快速、低成本、同時檢測多種重金屬等目的。本研究共使用兩種裝置,濾紙微電漿系統和毛細管電漿系統。濾紙微電漿系統電極製作簡易,利用刀片自我對準的特性即可製作出高度精確的電極間距,並使用自製升壓模組產生電漿;毛細管電漿系統利用微調平台使大頭針正對毛細管一端,毛細管另一端則接地。並定義大頭針為正極,毛細管端為負極,使用直流濾波電路產生電漿。 於濾紙電漿系統中,本研究分析不同種濾紙堆疊、滴水方式,以及光譜分析之平均,由於濾紙電漿系統會經歷濃縮、蒸發、激發等過程,產生火焰連續寬帶的光譜,因此採用平均三張光譜的方式作為定量依據。同時分析水量以及鎮流電阻對放光之影響。 於毛細管電漿系統中,本研究分析其液面擾動現象,由於電場之存在使毛細管液面產生不規則擾動,使得每次放電週期後都會伴隨著微小的放電。故本研究採用延長積分時間、光譜儀平均等功能,以減少遺漏資訊產生的誤差。接續分析電極間距對放電之影響,若間距過小則會產生連續放電,影響收光,因此本研究採用400、450 μm作為放電間距。本研究亦於此系統中並聯電容,使放電時間由電容控制,如此每次放電時長達毫秒等級,方才足夠激發溶液中的重金屬。 定量分析中,本研究以氮氣、OH、鎂作為定量背景值之選擇。氮氣和OH是本身存在於空氣中與水溶液中的物質,因此其激發機制與金屬較不相同,較難作為定量的背景。故本研究採用鎂作為背景,用以定量溶液中的鈣,偵測極限達1 ppm。 Microplasma has the features of high energy density, small size, and operating under atmospheric conditions. Therefore, this study attempted to develop a microplasma device to achieve rapid, low-cost, and simultaneous detection of various heavy metals. A total of two devices were used in this study, a filter paper microplasma system and a capillary microplasma system. The electrodes of the filter paper microplasma system were relatively easy to make, and the self-alignment feature of the blade could be used to make a highly accurate electrode gap. The home-made high voltage module was used to generate plasma; the capillary plasma system used translation stages to make the neddle face one end of the capillary, and the other end of the capillary was grounded. The neddle was defined as the positive electrode, and the capillary was the negative electrode, and a DC rectified circuit was used to generate plasma. In the filter paper microplasma system, we analyzed the different filter paper stacking, dripping methods, and spectral analysis. Since the filter paper plasma system underwent processes such as concentration, evaporation, and excitation, a continuous broadband spectrum of the flame was generated. The method of averaging three spectra was used as a quantitative basis. At the same time, the influence of water quantity and ballast resistance on light emission was analyzed. In the capillary system, we analyzed the phenomenon of liquid level disturbance. Due to the existence of the electric field, the capillary liquid surface produced irregular disturbances, so that each discharge cycle was accompanied by tiny discharges. Therefore, in this study, the methods of extending the integration time and averaging spectrometer were adopted to reduce errors caused by missing information. Also, we analyzed the effect of the electrode gap on discharge. If the gap was too small, continuous discharge occurred, which affected light emission. Therefore, 400 or 450 microns were used as the discharge gap in this study. Capacitors were also connected in parallel in this system to extend discharge time so that each discharge lasted as long as milliseconds, which was sufficient to excite the heavy metals in the solution. In quantitative analysis, nitrogen, OH, and magnesium were selected as quantitative background in this study. Nitrogen and OH are substances that exist in air and aqueous solutions, so their excitation mechanisms are different from those of metals, and they are difficult to use as quantitative backgrounds. Therefore, this study used magnesium as the background to quantify calcium in solution with a detection limit of 1 ppm. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/83830 |
DOI: | 10.6342/NTU202201789 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 化學工程學系 |
Files in This Item:
File | Size | Format | |
---|---|---|---|
ntu-110-2.pdf Restricted Access | 7.04 MB | Adobe PDF |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.