用于乙腈 - 水混合物中电位传感器标准化的一级标准缓冲溶液参考pH值的赋值

Assignment of reference pH-values to primary standard buffer solutions for standardization of potentiometric sensors in acetonitrile-water mixtures.

作者信息

Barbosa J, Sanz-Nebot V

机构信息

Department of Analytical Chemistry, University of Barcelona, Diagonal, 647, E-08028, Barcelona, Spain.

出版信息

Anal Bioanal Chem. 1995 Sep;353(2):148-55. doi: 10.1007/s0021653530148.

DOI:10.1007/s0021653530148

PMID:15048530

Abstract

Standard pH-values pH(PS) for seven primary standard buffer solutions in 0, 10, 30, 40, 50, 70 and 100% (w/w) acetonitrile-water mixed solvents at 298.15 K were determined according to the criteria recently endorsed by IUPAC. The preferential solvation of the ions in acetonitrile-water mixtures was studied in order to clarify the acid-base behaviour of the solutes in such mixtures. The influence of variation in the solvent composition on pH(PS) values was considered with a view to obtaining correlations that can be used to determine the pH(PS) values in any acetonitrile-water mixture up to 70% (w/w) acetonitrile. The pH(PS) values were then correlated with the weight and volume percentages and molar fraction of acetonitrile and with the Kamlet-Taft, pi(*), alpha and beta solvatochromic parameters of the acetonitrile-water mixtures. The equations obtained permit the standardization of potentiometric sensors in these mixtures.

摘要

根据国际纯粹与应用化学联合会（IUPAC）最近认可的标准，测定了七种主要标准缓冲溶液在298.15K温度下，于0%、10%、30%、40%、50%、70%和100%（w/w）乙腈 - 水混合溶剂中的标准pH值pH(PS)。研究了乙腈 - 水混合物中离子的优先溶剂化作用，以阐明溶质在此类混合物中的酸碱行为。考虑了溶剂组成变化对pH(PS)值的影响，目的是获得可用于确定乙腈含量高达70%（w/w）的任何乙腈 - 水混合物中pH(PS)值的相关性。然后将pH(PS)值与乙腈的重量百分比、体积百分比、摩尔分数以及乙腈 - 水混合物的Kamlet - Taft、π(*)、α和β溶剂化显色参数进行关联。所得方程可用于这些混合物中电位传感器的标准化。