微乳介质分光光度法测定微量锌

Spectrophotometric Determination of Trace Zinc in Microemulsion Medium

研究了以微乳液为介质时.锌与5-Br-PADAP的显色反应,选择了560 nm为测定波长,445nm为参比波长,锌含量在0.1-0.5μg/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 colour reaction of zinc（ Ⅱ ） with 2-（5-Bromo-2-pyridylazo）-5-diethylam inophenol in microemulsion was studied. Zinc（ Ⅱ ） reacts with 5-Br-PADAP to form a stable complex at pH 9.0. Its apparent molar absorptivity is ε= 1.064 × 10^5 L-（mol· cm）^-1 at 560nm. The Beer＇s low is obeyed in the range of 0.1-0.5μg/mL for zinc（ Ⅱ ）. The method is used to determine zinc（ Ⅱ ） in tea samples with .satisfactory results.