以衰減全反射-傅立葉轉換紅外光譜法結合化學動力學對過氧乙酸進行定量

Abstract

本研究提出一種通過衰減全反射傅立葉轉換紅外光譜法(Attenuated Total Reflectance-Infrared Fourier Transform Spectroscopy , ATR-FTIR) 定量過氧乙酸 (Peracetic Acid，PAA) 的方法。此方法的開發突破了以往使用滴定法所需時間受待測樣品濃度影響的限制，從檢測到套用關係式換算僅需不到兩分鐘。本方法除了測量時間快速且操作簡單之外，同時具備測量精準以及所需樣品量少的優點。本研究發現過氧乙酸在 1753 波數 處有一明顯特徵峰，該特徵峰比起以往研究的特徵峰在與其他成分圖譜比較的呈現上更為明顯，且從未被用於檢測濃度。用標準過氧乙酸以1753 波數 峰為基礎建立吸光度與濃度的檢量線，並以檢量線透過計算建立定量方程式，從而確認過氧乙酸濃度。透過在攝氏25度下，進行6種不同實驗條件合成的樣品之動力學計算確定了過氧乙酸的反應動力學方程式，即使反應尚未平衡，也可以透過方程式測量瞬時濃度，同時提供了準確動態即時監測的可行性。將本研究提出之動力學方程式所得到的平衡常數與速率常數，與利用傳統滴定法定量之平衡常數與速率常數作對比，通過對反應動力學計算的驗證，ATR-FTIR對過氧乙酸的定量分析方法是方便使用且可靠，甚至於動力學應用上準確性更勝於滴定法。Propose a method of quantitation of peracetic acid (PAA) by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR). This method is convenient than traditional titration method. Because the detection time of traditional titration method is depending on the sample’s concentration. But FTIR method only spend 2 minutes from detection to result. Besides short measure time and simply operate, this method has the advantage of less sample required and high accuracy.It was found that a characteristic peak of peracetic acid at 1753 wavenumber, is the clearest characteristic peak, and it never be used to detect the concentration. Using standard peracetic acid to build a calibration curve of absorbance versus concentration to gain the accurate concentration of peracetic acid. Propose the peracetic acid reaction kinetic equation by 6 different experiment synthesis in 25°C. No matter equilibrium or not, it is possible to gain the instantaneous concentration by the equation. It also represents the feasibility of accurate on-line monitoring. Compared the equilibrium constant and rate constant of equation with the titration’s one that proves the quantitation of peracetic acid by ATR-FTIR is credible.