Influence of pH and Concentration of Ionic Strength Adjuster (ISA) on the Performance of Nd(III) Ion Selective Electrodewith 4-Sebacoylbis(1-Phenyl-3-Methyl-5-Pyrazolone)(H2SbBP) as Ionophores

2019 ◽  
Vol 811 ◽  
pp. 153-157
Author(s):  
Husain Sosidi ◽  
Indra Noviandri ◽  
Buchari Buchari

4-Sebacoylbis (1-phenyl-3-methyl-5-pyrazolone) (H2SbBP) ligand has been successfully synthesized, characterized and used as ionophores in Nd (III) selective electrode, using polytetrafluoroethylene (PTFE) membranous as a support. Prior to use the PTFE membrane soaked ionophores 1.5% w/v in chloroform for 24 hours. The performance of electrode studied by seeing the influence of pH and concentration of KNO3 as a buffer solution ionic strength. Variations in pH of the solution was set at pH ranges between 1 to 10 using a solution of HCl and NaOH, while KNO3 concentration varied between 10-4 to 10-1 M. Nd3+ concentration range is between 10-6 up to 10-2 M. The best electrode performance was obtained at pH 5 and 10-2 M KNO3 concentration with a sensitivity of (18.5 ± 0.2) mV/decade and its response time less than 25 seconds.

1990 ◽  
Vol 70 (3) ◽  
pp. 411-424 ◽  
Author(s):  
F. L. WANG ◽  
P. M. HUANG

The feasibility of using a K ion-selective electrode (K-ISE) to monitor changes in solution K concentration in soil suspensions with time, under shaking conditions, was investigated and its significance in kinetics studies of K adsorption was discussed. Factors that affect the efficiency of the K-ISE method include the response time of the electrode, influence of suspended soil particles, shaking speed, and ionic strength of the system. The response time of the K-ISE decreased with increasing K concentration. Moreover, for a system with a solution K concentration greater than 10 mg K L−1, errors resulting from response delays were negligible when, under shaking conditions, observation time intervals were greater than 30 s. The influence of suspended soil particles on the K-ISE method was negligible for soil suspensions with a solution/soil ratio of 50:1 (vol/wt). Shaking significantly influenced K-ISE determination of solution K concentration. The degree of the influence of shaking on the determination of solution K appeared to be related to ionic factors of the systems. Shaking had much less influence on the soil suspensions, the filtrates and mixed CaCl2-KCl solutions than on pure KCl solutions. Satisfactory results were obtained by taking into account the response time, suspended soil particle and shaking speed factors and by adjusting the ionic strength of the calibration system (KCl standard solution series). Key words: Potassium ion-selective PVC membrane electrode, batch technique, kinetics, calibration system, electrode response time, suspended soil particle, shaking speed, ionic strength


1982 ◽  
Vol 47 (10) ◽  
pp. 2716-2723 ◽  
Author(s):  
Lubomíra Rexová-Benková ◽  
Jiřina Omelková ◽  
Vladimír Kubánek

Endo-D-galacturonanase of Aspergillus sp. was irreversibly adsorbed on polyethyleneterephthalate in an acetate 0.1 mol l-1 buffer solution of pH 4.2. Immobilization of the enzyme resulted in lowering of its activity, the measure of which depended on the amount of the enzyme fixed on the carrier. The highest relative activity (42.4%) had the preparation containing 5.25 mg of the enzyme per 1 g of the carrier. The velocity and intensity of the sorption of the enzyme depended on the ionic strength of the medium, whilst pH, on the other hand, was of no influence. Endo-D-galacturonanase immobilized in a 0.1 mol l-1 buffer was characteristic a) of its fixation strength in salt solutions of various ionic strength and pH, in a 3 mol l-1 guanidine solution, and also in sodium pectate and pectin solutions, b) of its high stability during a long-lasting storage at 4 °C, c) of its operational stability. The immobilization led to a partial change of the action pattern onto the high-molecular substrate, manifested in lowering the decrease of viscosity to degradation degree ratio.


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.


2021 ◽  
pp. 106903
Author(s):  
Caren Tanger ◽  
Michaela Müller ◽  
David Andlinger ◽  
Ulrich Kulozik

2013 ◽  
Vol 117 (46) ◽  
pp. 14576-14587 ◽  
Author(s):  
Sahika Inal ◽  
Leonardo Chiappisi ◽  
Jonas D. Kölsch ◽  
Mario Kraft ◽  
Marie-Sousai Appavou ◽  
...  

MRS Advances ◽  
2016 ◽  
Vol 1 (13) ◽  
pp. 861-867 ◽  
Author(s):  
Sanghamitra Mandal ◽  
Mohammed Marie ◽  
Omar Manasreh

ABSTRACTAn electrochemical glucose sensor based on zinc oxide (ZnO) nanorods is fabricated, characterized and tested. The ZnO nanorods are synthesized on indium titanium oxide (ITO) coated glass substrate, using the hydrothermal sol-gel technique. The working principle of the sensor under investigation is based on the electrochemical reaction taking place between cathode and anode, in the presence of an electrolyte. A platinum plate, used as the cathode and Nafion/Glucose Oxidase/ZnO nanorods/ITO-coated glass substrate used as anode, is immersed in pH 7.0 phosphate buffer solution electrolyte to test for the presence of glucose. Several amperometric tests are performed on the fabricated sensor to determine the response time, sensitivity and limit of detection of the sensor. A fast response time less than 3 s with a high sensitivity of 1.151 mA cm-2mM-1 and low limit of detection of 0.089 mM is reported. The glucose sensor is characterized using the cyclic voltammetry method in the range from -0.8 – 0.8 V with a voltage scan rate of 100 mV/s.


2019 ◽  
Vol 120 ◽  
pp. 748-755 ◽  
Author(s):  
Ruyi Li ◽  
Zicong Zeng ◽  
Guiming Fu ◽  
Yin Wan ◽  
Chengmei Liu ◽  
...  

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