The possibilities of application of iodine as a titrant in determination of sulfur compounds have been presented. The influence of the reaction medium, the nature of compounds, and the thiol–thione tautomerism on the reaction stoichiometry of sulfur compounds with iodine has been discussed. The conditions of volumetric titration with visual and potentiometric end-point detection and coulometric...

a poly(vinyl chloride) membrane based on a new a-dioxime derivative as membrane carrier was prepared andinvestigated as a cr(iii) selective electrode. the electrode exhibits a good potentiometric response for cr(iii)over a wide concentration range 1.0 x 10-6 to 1.0 x 10-1 m with a slope 19.5+0.5 mv/decade and low detectionlimit of 8.9 x 10-7 m. it has a fast response time < 15 s. the best perfo...

Chemical functional groups of surface layer (S-layer) proteins were chemically modified in order to evaluate the potential of S-layer proteins for the introduction of functional molecules. S-layer proteins are structure proteins that self-assemble into regular arrays on surfaces. One general feature of S-layer proteins is their high amount of carboxylic and amino groups. These groups are potent...

The acidity constants of some amino acids (Am) were determined by potentiometric pH titration. The stability constants of the 1:1 complexes formed between M2+: Ca2+, Mg2+, Mn2+, Co2+, Ni2+, Cu2+ or Zn2+ and Am2-, were determined by potentiometric pH titration in aqueous solution (I = 0.1 M, NaNO3, 25°C). The order of the stability constants was reported. It is shown that the stability of the bi...

The acidity constants of some amino acids (Am) were determined by potentiometric pH titration. The stability constants of the 1:1 complexes formed between M2+: Ca2+, Mg2+, Mn2+, Co2+, Ni2+, Cu2+ or Zn2+ and Am2-, were determined by potentiometric pH titration in aqueous solution (I = 0.1 M, NaNO3, 25°C). The order of the stability constants was reported. It is shown that the stability of the bi...

The main objective of this study was to develop an effective potentiometric saturation titration protocol for determining the aqueous intrinsic solubility and the solubility-pH profile of ionizable molecules, with the specific aim of overcoming incomplete dissolution conditions, while attempting to shorten the data collection time. A modern theory of dissolution kinetics (an extension of the No...

Carbon paste electrode was modified by disodium 2,4-diamino-7-methylbenzo[g] pteridine-5,10-dioxide to fabricate a sensor for potentiometric determination of vanadyl ion (VO2+) in aqueous medium. The new ligand was synthesized in three steps with high yield. The optimal composition of the carbon paste was made of graphite powder (64.5%), ionophore (16.6%), paraffin oil (17.8%), a...

A poly(vinyl chloride) membrane based on a new a-dioxime derivative as membrane carrier was prepared andinvestigated as a Cr(III) selective electrode. The electrode exhibits a good potentiometric response for Cr(III)over a wide concentration range 1.0 x 10-6 to 1.0 x 10-1 M with a slope 19.5+0.5 mV/decade and low detectionlimit of 8.9 x 10-7 M. It has a fast response time < 15 s. The best perfo...