摘要
提出了采用邻苯二胺分光光度法测定茶汤中的咖啡因.它是基于咖啡因在加热以及酸性条件下,能与邻苯二胺反应生成浅橙黄色苯并杂环类物质,此物质在488 nm处有最大吸收.该方法线性范围为4.0～25.0 μg/mL, 表观摩尔吸收系数ε=6.19×10^4 L·mol^-1·cm^-1,相对标准偏差RSD=1.2%,回收率为100%～105%.已用于茶汤中咖啡因的测定.
A new method for determining caffeinum by o-phenylenediamine spectrophotometry was studied. The basis is caffeinum could react with o-phenylenediamine and the yellow light orange resultant would be presented in acidic solutions. The linear range was 4.0-25.0 μg/mL, ε was 6.19×10^4, RSD was 1.2% and the recoveries were 100% - 105 %. It can be successfully applied to the assay of caffeinum.
出处
《分析试验室》
CAS
CSCD
北大核心
2006年第11期96-99,共4页
Chinese Journal of Analysis Laboratory
关键词
茶叶
咖啡因
分光光度法
Tea
Caffeinum
O-phenylenediamine
Spectrophotometry
