Potentiometric determination of silver thiolate formation constants using a Ag2S electrode

被引：69

作者：

Adams, NWH ^{[1
]}

Kramer, JR ^{[1
]}

机构：

[1] McMaster Univ, Sch Geog & Geol, Hamilton, ON L8S 4M1, Canada

来源：

AQUATIC GEOCHEMISTRY | 1999年 / 5卷 / 01期

基金：

加拿大自然科学与工程研究理事会;

关键词：

silver sulfide; thiols; formation constants;

D O I：

10.1023/A:1009699617808

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

Formation constants for silver thiolates were obtained by titration of the ligand in a constant temperature, ionic strength and pH medium and measuring the potential change at a Ag2S electrode. A non-linear equation was derived from which the first and second silver formation constants, beta(1)' and beta(2)', and the sulfide group acid dissociation constant, K-a', were determined. An overall estimate of the uncertainty in the derived parameters was obtained using a Monte Carlo approach. The procedure was compared to a previous work on AgHS degrees. Log beta(1)', log beta(2)' and -log K-a' results were obtained for cysteine (11.9 +/- 0.5, 15.2 +/- 0.4, 7.8 +/- 0.1), glutathione (12.3 +/- 0.3, 14.3 +/- 0.8, 8.8 +/- 0.3) and 3-mercaptopropanoic acid (12.0+/- 0.4, 14.0 +/- 0.4, 10.5 +/- 0.3) at 20 degrees C and 0.01 m ionic strength.

引用

页码：1 / 11

页数：11