Effects of Ion-Carrier Substituents on the Potentiometric-Response Characteristics in Anion-Selective Membrane Electrodes Based on Iron Porphyrins

ChemPhysChem ◽  
2004 ◽  
Vol 5 (5) ◽  
pp. 652-660 ◽  
Author(s):  
Saeed Shahrokhian ◽  
Hassan Seifi ◽  
Mojtaba Bagherzadeh ◽  
S. Reza Mousavi
Chemosensors ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Ville Yrjänä ◽  
Indrek Saar ◽  
Mihkel Ilisson ◽  
Sandip A. Kadam ◽  
Ivo Leito ◽  
...  

Solid-contact ion-selective electrodes with carbazole-derived ionophores were prepared. They were characterized as acetate sensors, but can be used to determine a number of carboxylates. The potentiometric response characteristics (slope, detection limit, selectivity, and pH sensitivity) of sensors prepared with different membrane compositions (ionophore, ionophore concentration, anion exchanger concentration, and plasticizer) were evaluated. The results show that for the macrocyclic ionophores, a larger cavity provided better selectivity. The sensors exhibited modest selectivity for acetate but good selectivity for benzoate. The carbazole-derived ionophores effectively decreased the interference from lipophilic anions, such as bromide, nitrate, iodide, and thiocyanate. The selectivity, detection limit, and linear range were improved by choosing a suitable plasticizer and by reducing the ionophore and anion exchanger concentrations. The influence of the electrode body’s material upon the composition of the plasticized poly(vinyl chloride) membrane, and thus also upon the sensor characteristics, was also studied. The choice of materials for the electrode body significantly affected the characteristics of the sensors.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1612
Author(s):  
Andrea Paut ◽  
Ante Prkić ◽  
Ivana Mitar ◽  
Perica Bošković ◽  
Dražan Jozić ◽  
...  

A novel ion-selective electrode with membranes based on iron(III) phosphate and silver sulfide integrated into a completely new electrode body design has been developed for the determination of iron(III) cations. The best response characteristics with linear potential change were found in the iron(III) concentration range from 3.97× 10−5 to 10−2 mol L−1. The detection limit was found to be 2.41× 10−5 mol L−1 with a slope of –20.53 ± 0.63 and regression coefficient of 0.9925, while the quantification limit was 3.97× 10−5 M. The potential change per concentration decade ranged from –13.59 ± 0.54 to –20.53 ± 1.56 for Electrode Body 1 (EB1) and from –17.28 ± 1.04 to –24 ± 1.87 for Electrode Body 2 (EB2), which is presented for the first time in this work. The prepared electrode has a long lifetime and the ability to detect changes in the concentration of iron cations within 20 s. Membrane M1 showed high recoveries in the determination of iron cations in iron(III) standard solutions (98.2–101.2%) as well as in two different pharmaceuticals (98.6–106.5%). This proves that this type of sensor is applicable in the determination of ferric cations in unknown samples, and the fact that all sensor parts are completely manufactured in our laboratory proves the simplicity of the method.


1982 ◽  
Vol 136 ◽  
pp. 399-401 ◽  
Author(s):  
Masaru Yamauchi ◽  
Akinori Jyo ◽  
Nobuhiko Ishibashi

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2297 ◽  
Author(s):  
Dana Vlascici ◽  
Nicoleta Plesu ◽  
Gheorghe Fagadar-Cosma ◽  
Anca Lascu ◽  
Mihaela Petric ◽  
...  

Pt(II) 5,10,15,20-tetra(4-methoxy-phenyl)-porphyrin (PtTMeOPP) was used in the construction of new ion-selective sensors. The potentiometric response characteristics (slope and selectivity) of iodide and bromide-selective electrodes based on (PtTMeOPP) metalloporphyrin in o-nitrophenyloctylether (NPOE), dioctylphtalate (DOP) and dioctylsebacate (DOS) plasticized poly(vinyl chloride) membranes are compared. The best results were obtained for the membranes plasticized with DOP and NPOE. The sensors have linear responses with near-Nernstian slopes toward bromide and iodide ions and good selectivity. The membrane plasticized with NPOE was electrochemically characterized using the EIS method to determine its water absorption and the diffusion coefficient into the membrane.


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