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本文报告用5—Br—PADAP分光光度法,测定茶叶中的微量铜,确定了铜与5—Br—PADAP生成络合物的最佳条件、络合物的组成比和克分子吸收系数。对茶叶消化液中共存离子的影响以及消除干扰,做了一些研究。分析了近十个茶样。测定结果:祁红与屯绿(皆为一级品)含铜分别为25.~6与16.~6ppm;速溶红茶与速溶绿茶(出口瓶装)则分别为13.~5与6.~4ppm,历次分析的重演性令人满意;加入铜标准液的回收率均达90%以上。
In this paper, 5-Br-PADAP spectrophotometry was used to determine trace copper in tea. The optimal conditions for the complex formation of copper with 5-Br-PADAP, the composition ratio of complex and the molecular absorption coefficient were determined. Some research has been done on the influence of coexisting ions in tea digestive juice and the elimination of interference. Analyzed nearly ten tea samples. Determination results: Qi Hong and Tunlun (all are the first grade) containing copper were 25. ~ 6 and 16. ~ 6ppm; instant black tea and instant tea (export bottled) were 13. ~ 5 and 6. ~ 4ppm The repeatability of previous analyzes was satisfactory. The recovery of copper standard solution was over 90%.