Ionized calcium in serum has been determined potentiometrically by using a calcium ion-selective electrode in a flow.through configuration. For 397 normal human adults the mean value for serum ionic calcium was 1.22 ± 0.09(2 SD) mmol/Iiter. Factors affecting the measurement-such as the pro. cedure for sample collection, sample storage, the preparation of standard solutions, the type of resin em...

In this study, to determine the pKa values of 2-ethoxy-6-(3-substitue-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl-azomethine)-phenyl benzoates (1-9) were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl acetone and N,N-dimethylformamide (DMF), graphs drawn for all cases. addition, effects molecular structure upon acidit...

In this paper, we report the photolithography manufacturing of solid- ion selective membrane electrodes ammonium and nitrate in a cleanroom, using ionophore I (nonactin) VI as starting materials. The developed probes are utilized with multipurpose electrochemical devices to potentiometrically monitor concentration ions. research results showed that, S-ISM can be used measure ions high selectivi...

Formation equilibria of dioxy vanadium (V) complex with alanine in acidic media (pH<2.3) has been investigated potentiometrically and spectrophotometrically. In this condition the 1:1 complex has the formula VO2Y, where Y¯ represent the fully dissociated aminocarboxylate anion. The stability constant of VO2Y was determined as log KVO2Y=11.32±<e...

3-Alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2a-g reacted with 4-diethylaminobenzaldehyde to afford the corresponding 3-alkyl(aryl)-4-(4-diethyl-aminobenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3a-g. The acetylation reactions of compounds 3a-e were investigated and compounds 4a-e were thus obtained. The new compounds were characterized using IR, (1)H-NMR, (13)C-NMR, UV and...

The aim of this study was (a) to determine the concentration of fluoride and cadmium in urine of 1240 children ( 635 boys, 605 girls) from Gdańsk, aged 7-14; and (b) to examine whether a correlation exists between age and sex of children, the location of the schools, and the urinary levels of fluoride and cadmium. Fluoride was determined potentiometrically using a fluoride-specific electrode. C...

Equilibrium constants have been measured potentiometrically for the mixed-ligand complexes, copper (U)-amines (A)-dipeptides (L). The aromatic amines (A) used are 5-nitro-l,lO-phenanthroline (Nphen), 2,2'-pyridyl benzimidazoline (pybz), 1,lO-phenanthroline (phen) and 2,2'-pyridyl imidazoline (pyz). The dipeptides used are glycylglycine (gg), glycyl-l-alanine (ga) and glyeyl-l-Ieucine (gl), The ...

The complexation reactions of some transition metal ions and 2-aminopyridine (2-ampy) were studied potentiometrically in aqueous solution at µ=0.1 M and 25 °C. The overall stability constants log β’s of all species are obtained by computer refinement of pH-volume data with using the BEST computer program. Several models were tested and the best one accepted according to the least sum of squ...

The stability constants and complexation reaction between L-glutamine, L-arginine andglycine with Zn (II) , Co (II) and Ni (II) were studied potentiometrically in aqueous solution at25° C and μ=0.1 M KNO3. The overall stability constants log β´s of all species are obtained bycomputer refinement of pH-volume data using BEST computer program. Several models weretested and the lowest δFIT, the bes...

The acidity constants of some synthesized protonated pyrazolo quinazoline compounds were determined potentiometrically at ionic strength of 0.1 M in DMF: water (60:40 v/v) system at different temperatures (298.15 K to 318.15 K). The pKa values have been found to increase with increasing electron-donating nature of substitutions. Some thermodynamics parameters such as enthalpy (ΔH°), Gibb’s free...