11012-L0206

111

3,000 千元

固定污染源管制

2022/02/16

2022/12/31

蕭大智

環檢所

潘銓泰

國立臺灣大學

大氣空氣

氣膠，微量金屬，粒徑解析，單顆粒電感耦合電漿質譜儀

Aerosol, Trace-Metal, Size-Resolved, Single Particle Inductively Coupled Plasma Mass Spectrometry

侯文哲、林逸彬

周立媞

02-33663366#55945

chou85524@gmail.com

本計畫為大氣微粒無機金屬現地質譜量測系統之建立，年度目標欲完成系統開發與測試分析，並將系統實際應用於室內環境，進行初步大氣微粒之量測，且需在連續6小時內完成至少3種不同金屬元素分析。此外，本計畫亦提供相關科普文章與技術擴散，用以作為日後建立和使用此套系統之技術援引參考。計畫共分成三部分逐一進行，第一部分為DMA-spICP-MS系統之開發及驗證，第二部分為GED-ICP-MS換氣系統建置及其效能評估，第三部分為開發系統實際運用在大氣環境採樣。 在DMA-spICP-MS的部分，本團隊使用30、50、80金標準奈米顆粒進行系統選徑之解析度驗證，結果顯示，選徑結果在較大尺徑下 (約大於70 nm)，分布有右偏之情形，此現象亦在過往文獻中被提及，團隊在經由實驗的驗證下，推論的主要原因為：微粒經過霧化送入選徑系統前並未乾燥完全，殘留在顆粒上之過多水珠造成選徑分布右偏，因此，團隊於系統中串聯一管式高溫爐將多餘水分去除，結果表明，在粒徑選徑下的右偏現象有明顯改善。欲使用大氣樣本於ICP-MS量測，氬氣的置換效率成為該系統之一大挑戰，本團隊於計畫中自製一GED換氣裝置，並與後端之ICP-MS串接。在GED的換氣效率的評估結果中，團隊最終選用樣品流 (Qa) 0.2 L/min，掃流(Qsweep)6 L/min參數進行後續實驗，此時換氣效率約達80%，在加入輔助氣流後最終進入ICP-MS氬氣純度約為96.5%。為評估系統可行性，GED-ICP-MS串接系統建立後，團隊先以流經HEPA之純氬氣作為空白樣本並與實驗室內採集之空氣樣本進行比對，空白樣本結果顯示，系統內微量金屬元件訊號低，且與實際空氣樣本具有明顯差距，表明系統在量測分析上具有可行性。隨後，為評估不同介質之空氣以及換氣率對GED-ICP-MS分析方法中檢量線建立及偵測極限的影響，本團隊分別使用零級空氣及過濾空氣建立標準品檢量線，並比較其偵測極限的差異。偵測極限藉由公式LOD=3.3×σy-intercept /slope計算。經研究發現，換氣率對檢量線斜率及偵測極限影響較低，偵測極限與檢量線線性有關。此外，在不同氣體介質對GED-ICP-MS偵測極限的影響中，發現ICP-MS的靈敏度受基質影響 (斜率約有1-2倍的差距)。本計畫最終將GED-ICP-MS系統實際於實驗室內進行大氣微粒連續6小時採樣分析，與過往文獻值相比，除Fe及Al有濃度偏高之情形，其他金屬皆與文獻數值相近。

氣膠，微量金屬，粒徑解析，單顆粒電感耦合電漿質譜儀

期末報告(定稿本).pdf

12MB

2023/1/15 上午 12:00:00

The purpose of this project is to establish a DMA-spICP-MS system for continuous analysis of trace metals in ambient particles for at least 6 h. Relevant journal articles and technology workshops were provided in this project as references for future system establishment and application. This project comprised of three main parts. First, we have established and validated a DMA-spICP-MS system. Second, a GED-ICP-MS system was developed and validated. Third, the system was used for real-time analysis in an ambient air environment. For the DMA-spICP-MS system, we used 30, 50, and 80-nanometer gold particles (AuNPs) to verify DMA. Compared to the TEM and spICP-MS results, the DMA results showed an obvious deviation with particle sizes larger than 70 nm. Based on previous studies, we hypothesized that excess liquid on the surface of the particles might influence the DMA-selected performance. As a result, a furnace was adopted in the system to remove unwanted liquids, which successfully improved the results. As we aimed to collect ambient particles in ICP-MS, the biggest challenge resided in the replacement of air for argon, which acted as the carrier gas in ICP-MS. To solve this problem, a homemade GED device was developed to replace air with argon for the subsequent ICP-MS analysis. In terms of the gas exchange efficiency of the GED, the sample flow (Qa) and sweep flow (Qsweep) were set as 0.2 L/min and 6.0 L/min, respectively. Under these conditions, the gas exchange efficiency was approximately 80%, and the purity of argon reached 96.5% along with the injection of auxiliary gas. For the system evaluation, clean pure argon was used as the blank sample. According to the results, the trace signal of the blank sample was significantly lower than those of other air samples, demonstrating the feasibility and reliability of our system. In addition, to understand the influence of different gas media and their air exchange rate under the detection limit (LOD=3.3×σy-intercept /slope) of GED-ICP-MS, we calibrated the system with zero gas and purified air. The results showed that the air exchange rate had a low influence on the slope of the calibration curve and the LOD. However, for different gas media, it was found that the sensitivity of ICP-MS was strongly affected by the matrix (the slope had a difference of approximately 1-2 times), which should be cautioned and addressed. Finally, the results of the continuous analysis of GED-ICP-MS for 6 h showed that, except for Fe and Al, the concentrations of all the other metals were similar to those in previous related studies.

Aerosol, Trace-Metal, Size-Resolved, Single Particle Inductively Coupled Plasma Mass Spectrometry