| Abstract: | 本研究中利用循環伏安法、安培法、方波伏安法等電化學分析技術配合流注式分析系統探討腐胺(putrescine)、屍胺(cadaverine)、精胺(spermine)與亞精胺(spermidine)等多胺(polyamine)與鍍銅白金電極間可能存在的電化學反應機制。為了確認鍍銅電極對多胺的電訊號如何產生，研究中在流注式分析系統中連續流注多胺溶液並使用雙工作電極加以偵測，利用上游鍍銅電極進行氧化偵測、下游白金電極進行陰極沉積的工作模式確認在偵測時會溶出銅離子；並進一步利用多胺溶液浸泡銅氧化物，使用方波伏安法確認浸泡液中含有銅離子存在，藉以上實驗結果證實鍍銅電極對於多胺的電訊號源自於銅電極表面惰性氧化層溶解後由內部零價銅再生而產生。
在確認鍍銅電極偵測多胺之機制後，研究中進一步探討得知在流注式分析統(FIA)中偵測多胺之最佳條件如下：偵測電位為0.25V、載體溶液為0.1 M磷酸緩衝溶液、環境pH值為10、載體流速為0.5 ml/min、樣品迴路體積為50μl。對於腐胺、屍胺、精胺與亞精胺等之偵測極限與線性範圍分別為：23.50 μM、32.58 μM - 1mM；381.6 μM、529.1 μM - 10mM；456.0 nM、0.6323μM - 100μM；337.7 nM、0.4682μM - 100 μM，其相關係數均在0.99以上，連續偵測各種多胺之相對標準偏差均在5%以下，並可以避免常見之人體干擾物之訊號干擾。
Cyclic voltammetry, amperometry, and square wave voltammetry were used in this research to discuss the electrochemical mechanism might exist between electrodeposited copper electrodes and polyamines, such as putrescine, cadaverine, spermine, and spermidine. Continuous flow of polyamine solution was injected and detected by dual electrode in flow injection analysis system for assuring how the current response on electrodeposited electrode was produced by polyamines, it shows that cupric ion dissolves from the electrodeposited copper electrode surface when detecting polyamines while using upstream electrode to perform anodic detection and downstream electrode for cathodic electrodeposition. Then, after immersing copper oxides in polyamine solution, cupric ion was found by square wave voltammetry. It can be concluded that the anodic current response produced by polyamines on the electrodeposited copper electrode is produced by the oxidization of Cu(0) to regenerate the passive oxide layer dissolved by polyamines passing through the electrode surface.
After the detection mechanism was certified, the optimization of flow injection(FIA) system was done and it show that the best conditions are 0.25 V as detection voltage, 0.1 M pH 10 phosphate buffer as carrier solution, 0.5 ml/min as flow rate and the sample loop is 50μl. The detection limit of putrescine, cadaverine, spermine, and spermidine were 23.50 μM,32.58 μM - 1mM; 381.6 μM, 529.1 μM - 10mM; 456.0 nM, 0.6323μM - 100μM, 337.7 nM, 0.4682μM - 100 μM, respectively, the RSD of sequential detection were all below 5%, and the common interference in human body can be avoided. |
