Determination of binding constants of cyclodextrin complexes with metal polypyridyl species by affinity CE using their ionic strength corrected and uncorrected actual mobilities

0538653 - ÚOCHB 2021 CZ eng A - Abstrakt
Sázelová, Petra - Koval, Dušan - Severa, Lukáš - Teplý, Filip - Vigh, G. - Kašička, Václav
Determination of binding constants of cyclodextrin complexes with metal polypyridyl species by affinity CE using their ionic strength corrected and uncorrected actual mobilities.
Czech Chemical Society Symposium Series. Roč. 18, č. 3 (2020), s. 82. ISSN 2336-7202.
[Sjezd českých a slovenských chemických společností /72./. 06.09.2020-09.09.2020, Praha]
Grant CEP: GA ČR(CZ) GA18-02597S
Institucionální podpora: RVO:61388963
Klíčová slova: binding constants * affinity capillary electrophoresis * ionic strength
Obor OECD: Analytical chemistry
https://sjezd72.csch.cz/wp-content/uploads/2020/09/Sjezd-Praha-2020-tisk.pdf

The apparent binding constants and limiting mobilities of the multiply charged complexes of the Δ- and Λenantiomers of [Ru(bpy)3] 2+, [Ru(phen)3] 2+ and [Fe(phen)3] 2+ associates1 with 2,3-diacetylated-6-sulfated-(α,β,γ)- cyclodextrins (CDs) were determined by affinity capillary electrophoresis (ACE)2 . Two limiting models were tested for the ionic strength correction of the actual mobilities based on an empirical relation for the ionic strength correction of multivalent ionic species3 . In model 1, the nominal values of the charge numbers (zS,nom) and analytical concentrations (cS,nom) of the above CD selectors in the background electrolytes (BGEs) were applied for calculation of the BGE ionic strength, as usually. In model 2, the CD selectors were considered as singly charged species (zS = –1) with |zS,nom|-times higher concentrations in the BGE than their analytical concentrations (cS = |zS,nom| × cS,nom) in the calculation of the BGE ionic strength. In all three cases – with uncorrected actual mobilities as well as with actual mobilities corrected according to the two limiting models – the measured effective mobilities of the above enantiomers fit well the theoretical curves of their mobility dependences on the CD selectors concentrations in the BGE, with high average coefficients of determination (R2 = 0.9890–0.9995). The best physico-chemically meaningful values of the apparent binding constants and the limiting mobilities of the enantiomer-CDs complexes with low RSDs were obtained using the actual mobilities of the species involved corrected according to model 2.
Trvalý link: http://hdl.handle.net/11104/0316944