利用HPLC及電化學方法檢測市售飲料中咖啡因含量

為了瞭解台灣市售飲料中咖啡因含量是否符合標準，本研究於2012年4月至11月間調查市售包裝及非包裝飲料中咖啡因含量，依據中華民國國家標準CNS-9432號檢驗法進行檢測，並將結果與電化學方法結果進行比對。本次檢測市售包裝飲料檢體共91件（其中咖啡飲料41件、茶類飲料39件和提神飲料11件）及市售非包裝飲料檢體23件（包括咖啡飲料8 件及茶類飲料15 件）。以高效能液相層析儀（High Performance LiquidChromatography；HPLC）分析樣品結果顯示包裝咖啡飲料、茶類飲料和提神飲料中咖啡因含量分別介於116－863 ppm、0－264 ppm 和0－595 ppm 及非包裝咖啡飲料和茶類飲料中咖啡因含量分別介於378~1,287 ppm和154～333 ppm。市售包裝咖啡飲料、茶類飲料和提神飲料中咖啡因含量超過標示10%以上的分別有10件、1件和2件，其咖啡飲料最高超過包裝標示含量的106%。市售包裝與非包裝的咖啡飲料其咖啡因含量相近，而市售包裝與非包裝的茶類飲料相比，非包裝茶類飲料咖啡因平均的含量比包裝茶類飲料高。此外，本研究電化學方法是利用奈米金修飾網版電極，以循環伏安法（Cyclic voltammetry，CV）進行上述檢體咖啡因含量之檢測比對，所獲得的咖啡因含量與傳統方法比對結果顯示，其相對百分比達92%以上，證實此方法可應用至咖啡因濃度之檢測，未來可改良檢測條件，以提昇方法的敏感度，進而提高樣品檢測的精準度。

關鍵字

咖啡因；循環伏安法；電化學；奈米金修飾網版電極

並列摘要

To ensure that caffeine content of packaged and unpackaged beverages comply with their food labeling requirements, this study was to investigate the caffeine content of 91 commercially packaged beverages including 41 coffee drinks, 39 tea drinks, 11 energy drinks, and 23 unpackaged drinks including 8 coffee drinks and 15 tea drinks using the high performance liquid chromatography (HPLC) method in accordance with the Chinese National Standard inspection (CNS)-9432, as compared with the electrochemical method during the period of April to November, 2012. The results showed that the caffeine content of packaged coffee, tea and energy drinks ranged from 116 to 863 ppm, 0 to 264 ppm and 0 to 595 ppm, respectively, and the caffeine content of unpackaged coffee and tea drinks ranged from 360 to 1,293 ppm and 154 to 333 ppm, respectively. The caffeine content in 10 packaged coffee drinks, 1 tea drink and 2 energy drinks were found exceed 10% of their caffeine content labeling in which one coffee drink exceeded 106% labeled caffeine content. The caffeine contents in commercially packaged coffee drinks were similar to that of unpackaged coffee drinks whereas the caffeine contents in commercially unpackaged tea drinks were more than that of packaged tea drinks. In addition, the electrochemical method based on cyclic voltammetry with gold-nanostructured screenprinted electrode was used to detect the caffeine content of those drinks above and compared the accuracy to the HPLC method. The electrochemical method showed above 92% relative percentage as compared to the HPLC method. The electrochemical detection could be an alternative method for determining the caffeine content. The parameters of the detection conditions may be required to revise in order to improve the accuracy and sensitivity of the method in the further study.

並列關鍵字

Caffeine ； cyclic voltammetry ； electrochemical ； gold-nanostructured screen-printed electrode

國際替代計量

利用HPLC及電化學方法檢測市售飲料中咖啡因含量

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