EHPG与Pb（Ⅱ）结合的紫外差光谱研究

The Spectroscopic Studies on the Binding of Pb（ Ⅱ ） to EHPG

在pH7．4,0．1mol·L^-1Hepes缓冲溶液及室温条件下，使用紫外吸收差光谱进行了Pb（Ⅱ）对N，N’-乙烯-二[2～（2-羟基苯基）苷氨酸]（EHPG）的滴定。结果表明Ph（Ⅱ）与EHPG形成1：1的配合物。Pb（Ⅱ）与EHPG结合后其紫外差光谱在245nm和291nm处出现吸收峰；配合物在291nm的摩尔吸光系数是1．78×10^3cm^-1·mol^-1·L；条件稳定常数是1gK=12．51±0．32。

Interaction of ethylene - N, N＇ - bis （ o - hydioxyphenylglycine） （EHPG） with Pb2＋ were investigated by both UV difference and fluorescent spectra. Both results showed that the molar ration of the complex was most likely 1 ：1. Pb2＋ binding produces peaked at 245nm and 291nm. The molar absorptivity of Pb^2＋ to EHPG at 291nm was 1. 783 × 10^3cm^-1 . mol^-1 . L The conditional stability constant for Pb^2＋ binding to EHPG was determined to be lgK = 12. 51 ＋0. 32 in 0.1 mol. L^-1