本研究利用修飾網版印刷碳電極以 HPLC-ECD 的方式發展出快速、再現性佳和簡單應用的電化學法來測定水溶性的植物萃取物，以便建立體外抗氧化能力評估。並將其結果與總多酚含量測定 ( Folin-Ciocalteu method )、DPPH 自由基清除能力測試等進行比較。在分光光度計實驗中，對烏龍茶茶葉、銅鑼杭菊以冷水、熱水、超音波等三種方式進行萃取。萃取液分別以總多酚含量測定及 DPPH 自由基清除能力測試進行檢測。在相同萃取時間下兩者結果皆得到熱水萃取大於超音波、冷水萃取的總抗氧化能力，且萃取時間越久，萃取液的總抗氧化能力越佳。在電化學實驗中，以化學修飾方式將網版印刷碳電極 ( SPCE ) 表面進行修飾，在循環伏特安培法測定下，可得知修飾網版印刷碳電極能提高其電活性並減少測定過程中產生的樣品干擾訊號。本實驗中烏龍茶茶葉在 HPLC-UV ( 244nm / 271nm ) 測定中可分離得到約 20 幾種化合物存在，但需以適合的偵測波長對化合物的官能基進行偵測。利用 HPLC-ECD 測定，在安培法測定下可得到約 10 幾種具有電活性的化合物，比較這些化合物的滯留時間、電流值，便能對烏龍茶中抗氧化成分進行快速篩選，並能針對抗氧化成分的特性作進一步探討。 In this study the modified screen printed carbon electrode (M-SPCE) method followed by HPLC-ECD analysis was developed a fast, good reproducibility and simple application for electrochemical method and evaluated antioxidant content in water-soluble plant extracts for assessment.The result was compared with the total phenolic content assay ( Folin-Ciocalteu method ) and DPPH radical scavenging activity assay. That oolong tea leaves and Chrysanthemum were extracted by three ways such as cold water, hot water, ultrasound in the experiment of spectrophotometer.The extracts were detected by total polyphenol content and DPPH radical scavenging activity assay. Both results were obtained that total antioxidant capacity of extracts by hot water was better than ultrasonic and cold water in the same time. As extracted time went on , the extracts had total antioxidant capacity became better.The screen printed carbon electrodes ( SPCE ) expressed their surfaces chemically modified. In the experiment of electrochemical, the scheme shows high sensitivity and limited interferences for cyclic voltammetry.In this study, about 20 kinds of compounds were isolated by HPLC-UV ( 244nm / 271nm ) from oolong tea leaves. But this method needed the adaptive wavelength to detect functional groups in organic compounds. About 10 kinds of electrically active compounds were detected by amperometry from oolong tea leaves. Compared with retention times and current (A) of these compounds. that was able to rapid screening for antioxidants from oolong tea,and could be further explored for properties from antioxidant.
