scholarly journals Use of the Copper(II) Ion-selective Electrode for the Determination of the Stability Constant of Binuclear Copper(II) Complex with 3,6-Dioxaoctane-1,8-diamine-N,N,N′,N′-tetraacetric Acid

1980 ◽  
Vol 53 (9) ◽  
pp. 2548-2551 ◽  
Author(s):  
Kunio Ohzeki ◽  
Masakuni Saruhashi ◽  
Tomihito Kambara
Author(s):  
Sarizhat D. Tataeva ◽  
Arsen Sh. Ramazanov ◽  
Victoriya S. Magomedova ◽  
Kurban E. Magomedov ◽  
Ruslan Z. Zeynalov

The possibility of approbation of an ion-selective electrode based on diantipyrylpropylmethane for determination of lead is considered in the work. Optimization of the membrane composition of an ion-selective electrode was carried out with the change of weight ratios of membrane components. The best results were obtained with the addition of potassium tetraphenylborate by weight of 1.35%. According to the obtained experimental steepness, a membrane of composition (wt.%) was chosen: PVC (32.62), o-PFOE (65.25), DAPPM (1.35), NaTPB (0.78). The linearity interval of the electrode with an optimized composition of the membrane was observed in the concentration range of 10-6 -10-1 M, with a response of 10 s. The slope of the Pb-SE function is 27.4 ± 0.5 mV / pC. The influence of the acidity of the medium on the Pb-SE response was studied. At the pH=3-5 a potential of the Pb-SE for the compositions remains stable with a drift not more than 2 mV. For a given electrode, the selectivity coefficients were determined by the method of bionic potentials with respect to some d-elements, as well as alkaline and alkaline-earth metals. The influence of zinc, cadmium, mercury and copper ions on the membrane response is significant, which requires the use of various masking reagents in potentiometric analysis in the presence of these ions. To increase the selectivity of the membrane to lead ions, 0.1 M NH4SCN was introduced into the solution under analysis to bind Cu (II), Zn (II), Hg (II) and Cd (II) ions to stronger ammonium complexes. The proposed electrode favorably differs by the interval of the determined concentrations (M) - 10-6 - 10-1; high selectivity, and also increases in the stability of the membrane due to high lipophilicity relative to diantipyrylmethane.Forcitation:Tataeva S.D., Ramazanov A.Sh., Magomedova V.S., Magomedov K.E., Zeynalov R.Z. Diantipyrylpropylmethane as electrode-active components of membrane of lead selective electrode. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 23-28


Holzforschung ◽  
2016 ◽  
Vol 70 (8) ◽  
pp. 733-738 ◽  
Author(s):  
Kim Granholm ◽  
Tomasz Sokalski ◽  
Andrzej Lewenstam ◽  
Ari Ivaska

Abstract The calcium binding ligand in black liquor (BL) has been investigated by the new CSSP (circumvention of slope and standard potential) method, which converts the potential of an ion-selective electrode to concentration or activity. The advantage of this approach is that the knowledge about the electrode standard potential and the slope of the calibration curve is not needed. Instead, two activities of calcium ion on the titration curve have to be estimated, for instance the starting activity before the titration begins and the activity at the end of the titration in presence of a large excess of the titrant. A solid-contact Ca2+-selective electrode was used to determine the stability constant of the Ca binding ligand in BL. In addition, the concentration of free and bound calcium was determined. The total Ca concentration obtained by the CSSP approach agreed well to that obtained by the ICP-OES technique. Other metal ions did not influence the determination if the BL concentration is around 3%.


2016 ◽  
Vol 5 (10) ◽  
pp. 4920
Author(s):  
Amar M. Ali ◽  
Hussain. J. Mohammed*

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood. 


1981 ◽  
Vol 46 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Josef Veselý

Titration of sulphates with lead perchlorate employing lead ion selective electrode indication was studied using additions of various organic solvents at different pH' and ionic strength values. As the optimum emerged systems with 60-70% 1,4-dioxane, pH' 5.3-5.6. After dehydration with sodium hydroxide, dioxane must be freed from the electrode surface-oxidizing impurities by their reduction with sodium metal and subsequent distillation. The method was applied to determination of sulphates in mountain spring waters. Units of ppm can be determined; the limit of determination, however, depends considerably on the content of dioxane, total salt content in the sample, and speed of the semi-automatic titration. Lead can be determined with EDTA in concentrations down to c(Pb2+) = 5 . 10-6 mol l-1.


Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 155
Author(s):  
Yan Su ◽  
Ting Liu ◽  
Caiqiao Song ◽  
Aiqiao Fan ◽  
Nan Zhu ◽  
...  

As an essential electrolyte for the human body, the potassium ion (K+) plays many physiological roles in living cells, so the rapid and accurate determination of serum K+ is of great significance. In this work, we developed a solid-contact ion-selective electrode (SC-ISE) using MoS2/Fe3O4 composites as the ion-to-electron transducer to determine serum K+. The potential response measurement of MoS2/Fe3O4/K+-ISE shows a Nernst response by a slope of 55.2 ± 0.1 mV/decade and a low detection limit of 6.3 × 10−6 M. The proposed electrode exhibits outstanding resistance to the interference of O2, CO2, light, and water layer formation. Remarkably, it also presents a high performance in potential reproducibility and long-term stability.


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