微乳液分光光度法测定茶叶中的锌

Spectrophotometric Determination of Trace Zinc in Microemulsion Medium

研究了以微乳液为介质时，锌与1-（2-吡啶偶氮）-2-萘酚（PAN）的显色反应，选择了565nm为测定波长，470nm为参比波长，锌含量在0．2—0．8μg／mL范围内符合比尔定律。该法用于测定茶叶中的锌含量，结果满意。

The color reaction of zinc （Ⅱ） with 1- （2-pyridylazo） -2-naphthol in microemulsion has been studied. Zinc （ Ⅱ ） reacts with PAN to form a stable complex at pH 9.0. Its apparent molar absorptivity is ε = 7.09 × 10^4 L· （mol·cm）^-1 at 565 nm nm. The Beer＇s law is obeyed in the range of 0.2 -0.8μg/mL for zinc （ Ⅱ ）. The method is used to determine zinc （ Ⅱ ） in tea samples with satisfactory results.