摘要
基于不可逆电对的流动注射双安培检测原理，建立了快速检测茶叶中单宁的新方法。使用经阳极化处理的双铂电极，通过偶合单宁在一支电极上的催化氧化和氧化铂在另一支电极上的还原两个不可逆电极过程，在外加电位差为０Ｖ时，单宁的氧化电流与其浓度在１．０ × １０^（－６）～１．０ × １０^（－４）ｍｏｌ／Ｌ范围内呈线性关系，检出限为６．０ × １０^（－７）ｍｏｌ／Ｌ（Ｓ／Ｎ＝２）。连续４２次测定１．０ × １０^（－５）ｍｏｌ／Ｌ单宁，电流值ＲＳＤ＝１．２％。本法比现行国家标准方法简单、快速、灵敏，分别对市售绿茶、花茶、乌龙茶、红茶中单宁含量进行测定，结果令人满意。
Based on the flow injection-biamperometry for irreversible couple system, a method has been established for the determination of tannin in tea. Using two preanodized platinum electrodes, the biamperometric detection system was setup by coupling the oxidation of tannin at an electrode and the reduction of platinum oxide at the other. Under the applied potential difference of 0 V, the linearity between current and tannin concentration was obtained over the range 1.0 x 10(-6) similar to 1.0 x 10(-4) mol/L with the detection limit 6.0 x 10(-7) mol/L (S/N = 2). The relative standard derivation of 1.2% was obtained for 42 successive determinations of 1.0 x 10(-5) mol/L tannin. The procedure is superior to the current official method for its simplicity, high efficiency and high sensitivity, and has been used for the determination of tannin in commercial samples of green tea, jasmine tea, wulong tea and red tea with satisfactory results.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2002年第2期210-213,共4页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金资助课题(No.29875017)
