Unified pH Measurements of Ethanol, Methanol, and Acetonitrile, and Their Mixtures with Water

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00177016%3A_____%2F21%3AN0000054" target="_blank" >RIV/00177016:_____/21:N0000054 - isvavai.cz</a>

Result on the web

<a href="https://www.mdpi.com/1424-8220/21/11/3935" target="_blank" >https://www.mdpi.com/1424-8220/21/11/3935</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/s21113935" target="_blank" >10.3390/s21113935</a>

Result language

angličtina

Original language name

Unified pH Measurements of Ethanol, Methanol, and Acetonitrile, and Their Mixtures with Water

Original language description

Measurement of pH in aqueous-organic mixtures with different compositions is of high importance in science and technology, but it is, at the same time, challenging both from a conceptual and practical standpoint. A big part of the difficulty comes from the fundamental incomparability of conventional pH values between solvents ((s)pH, solvent-specific scales). The recent introduction of the unified pH (pH(abs)) concept opens up the possibility of measuring pH, expressed as pH(abs)(H2O), in a way that is comparable between solvent, and, thereby, removing the conceptual problem. However, practical issues remain. This work presents the experience of the authors with measuring pH(abs)(H2O) values in mixtures of methanol, ethanol, and acetonitrile, with water, but without the presence of buffers or other additives. The aim was to assigned pH(abs)(H2O) values to solvent-water mixtures using differential potentiometry and the 'pH(abs)-ladder' method. Measurements were made of the potential difference between glass electrodes immersed in different solutions, separated by an ionic liquid salt bridge. Data were acquired for a series of solutions of varying solvent content. This work includes experiences related to: a selection of commercial electrodes, purity of starting material, and comparability between laboratories. Ranges of pH(abs)(H2O) values for selected compositions of solvent-water mixtures are presented.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

<a href="/en/project/8B18003" target="_blank" >8B18003: Realisation of unified pH Scale</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Sensors

ISSN

1424-8220

e-ISSN

1424-8220

Volume of the periodical

21

Issue of the periodical within the volume

11

Country of publishing house

CH - SWITZERLAND

Number of pages

16

Pages from-to

—

UT code for WoS article

000660662600001

EID of the result in the Scopus database

2-s2.0-85107281800