全反射X光螢光光譜儀－－應用於茶葉微量元素的測定

Trace Element Analysis of Tea Samples by Total-Reflection X-Ray Fluorescence

本研究利用全反射X光螢光光譜儀及感應耦合電漿質譜儀測定經由酸消化的茶葉中所含之微量元素，包括Mn、Fe、Ni、Cu、Zn及Sr等。進行分析之材料是來自於市面上所販售之9種不同種類（紅茶、綠茶及烏龍茶）及等級的茶葉。試驗結果顯示，以全反射X光螢光光譜儀與感應耦合電漿質譜儀所檢測出之Mn、Fe、Ni及Sr等四種重金屬元素測值大致相近，顯示以TXRF檢測此四種重金屬含量，具有其可信度。在不同品牌的茶葉檢測方面，天仁品牌的綠茶、原片鮮綠茶及烏龍茶的Mn、Fe、Ni、Zn及Cu元素的含量有較立頓品牌綠茶和烏龍茶、台大實驗林茶葉及有機茶高之趨勢；台大實驗林茶葉的各種微量元素含量皆低於其他品牌。 Total-Reflection X-ray Fluorescence Spectrometer (TXRF) and Inductively Coupled Plasma- Atomic Emission Spectrometry (ICP-AES) were used for the simultaneous determination of trace elements (Mn, Fe, Ni, Cu, Zn, Sr) in tea samples which were prepared by acid digestion. In this study, 9 tea samples, which were collected with different kinds (green, red, and black tea) and/or qualities were analyzed from the market. The contents of Mn, Fe, Ni and Sr in tea leaves was almost the same values by ICP and TXRF analyzed, representing accuracy by TXRF. In terms of different brand tea samples, the contents of Mn, Fe, Ni, Zn and Cu in Ten Ren green tea, Ten Ren whole laves fresh green tea and Ten Ren oolong tea were significantly higher than the samples of Lipton green Tea, Lipton oolong tea, Organic tea and Taiwan University Forest Experimental tea. All kinds of trace elements in samples of Taiwan University Forest Experimental tea is significantly lower than other teas.

Total-Reflection X-ray Fluorescence Spectrometer (TXRF) and Inductively Coupled Plasma- Atomic Emission Spectrometry (ICP-AES) were used for the simultaneous determination of trace elements (Mn, Fe, Ni, Cu, Zn, Sr) in tea samples which were prepared by acid digestion. In this study, 9 tea samples, which were collected with different kinds (green, red, and black tea) and/or qualities were analyzed from the market. The contents of Mn, Fe, Ni and Sr in tea leaves was almost the same values by ICP and TXRF analyzed, representing accuracy by TXRF. In terms of different brand tea samples, the contents of Mn, Fe, Ni, Zn and Cu in Ten Ren green tea, Ten Ren whole laves fresh green tea and Ten Ren oolong tea were significantly higher than the samples of Lipton green Tea, Lipton oolong tea, Organic tea and Taiwan University Forest Experimental tea. All kinds of trace elements in samples of Taiwan University Forest Experimental tea is significantly lower than other teas.