食品科学

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茶叶和饮料中咖啡因的快速电化学测定

陈立新1,江 帆2,党丽敏1,周 原1   

  1. 1.湖南工程学院化学化工学院,湖南 湘潭 411104;2.深圳出入境检验检疫局工业品检测技术中心,广州 深圳 518067
  • 出版日期:2014-10-25 发布日期:2014-11-07
  • 基金资助:

    湖南省教育厅科研项目(10C0555)

Rapid Analysis of Caffeine in Tea and Drink by Electrochemical Method

CHEN Li-xin1, JIANG Fan2, DANG Li-min1, ZHOU Yuan1   

  1. 1. College of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China;
    2. Testing and Technology Centre of Industrial Products, Shenzhen Entry-Exit Inspection and Quarantine Bureau, Shenzhen 518067, China
  • Online:2014-10-25 Published:2014-11-07

摘要:

应用电化学方法在玻碳电极对茶叶和饮料中的咖啡因进行测定研究。讨论不同环境底液及其pH值、扫描速度、静止时间对峰电流的影响,并研究电化学检测咖啡因的重复性、稳定性和干扰实验。结果发现,咖啡因在pH 6.60的磷酸二氢钠-磷酸氢二钾缓冲底液中于+1.486 V左右产生一个明显的氧化峰。方波伏安法和差分脉冲伏安法的线性范围分别为2.0×10-6~2.0×10-3、1.8×10-6~1.0×10-3 mol/L,检出限分别为3.0×10-7、5.0×10-6 mol/L。该方法可快速测定茶叶盒饮料中的咖啡因,简单高效。

关键词: 咖啡因, 循环伏安法, 差分脉冲伏安法, 方波伏安法, 玻碳电极

Abstract:

A rapid method for the determination of caffeine in tea and drink has been established. Cyclic voltammetry (CV),
square wave voltammetry (SWV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical
behavior of caffeine at a glassy carbon electrode. The caffeine showed a sensitive oxidation peak at + 1.486 V using CV
in a NaH2PO4-K2HPO4 buffer solution at pH 6.60. The impacts of buffer solution, pH, accumulation time and scan rate
were discussed. The peak current was linear to caffeine concentration ranging from 2.0 × 10-6 to 2.0 × 10-3 mol/L with
a detection limit of 3.0 × 10-7 mol/L by SWV, and ranging from 1.8 × 10-6 to 1.0 × 10-3 mol/L with a detection limit of
5.0 × 10-6 mol/L by DPV. In addition to satisfactory reproducibility and reversibility, the methods exhibited sufficient
selectivity and thus were suitable for rapid determination of caffeine in tea and drink.

Key words: caffeine, cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, glassy carbon electrode

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