Naslov
Determination of thermodynamic acidity constants and limiting ionic mobilities of weak electrolytes by capillary electrophoresis using a new free software AnglerFish

Autori
Malý, Michal ; Boublík, Milan ; Pocrnić, Marijana ; Ansorge, Martin ; Lorinčíková, Kateřina ; Svobodová, Jana ; Hruška, Vlastimil ; Dubský, Pavel ; Gaš, Bohuslav

Izvornik
Electrophoresis (0173-0835) 00 (2019); 1-9

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
capillary electrophoresis ; dissociation constant ; limiting mobility ; nonlinear regression ; software

Sažetak
Thermodynamic acidity constants (acid or acid- base dissociation constants, sometimescalled also as ionization constants) and limiting ionic mobilities (both of them at definedtemperature, usually 25°C) are the fundamental physicochemical characteristics of a weakelectrolyte, that is, weak acid or weak base or ampholyte. We introduce a novel methodfor determining the data of a weak electrolyte by the nonlinear regression of effective elec-trophoretic mobility versus buffer composition dependence when measured in a set ofBGEs with various pH. To correct the experimental data for zero ionic strength we use theextended Debye-Hückel model and Onsager- Fuoss law with no simplifications. Contraryto contemporary approaches, the nonlinear regression is performed on limiting mobilitydata calculated by PeakMaster’s correction engine, not on the raw experimental mobilitydata. Therefore, there is no requirement to perform all measurements at a constant ionicstrength of the set of BGEs. We devised the computer program AnglerFish that performsthe necessary calculations in a user- friendly fashion. All thermodynamic pKa values andlimiting electrophoretic mobilities for arbitrarily charged substances having any numberof ionic forms are calculated by one fit. The user input consists of the buffer compositionof the set of BGEs and experimentally measured effective mobilities of the inspected weakelectrolyte.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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