scholarly journals Bis(trans-cinnamaldehyde)-1,3-propanediimine) mercury(II)chloride, [Hg(BPPPB)Cl2] as Carrier for Construction of Iodide Selective Electrode

2012 ◽  
Vol 9 (4) ◽  
pp. 2565-2574
Author(s):  
G. Karimipour ◽  
S. Gharaghani ◽  
R. Ahmadpour

Highly selective poly(vinyl chloride) (PVC) membrane of iodide ion selective electrode based on the application of bis(trans-cinnamaldehyde)-1,3-propanediimine)mercury(II)chloride [Hg(BPPPB)Cl2] as new carrier by coating the membrane ingredient on the surface of graphite electrodes has been reported. The effect of various parameters including membrane composition, pH and possible interfering anions on the response properties of the electrode were examined. At optimum conditions, the proposed sensor exhibited Nernstian responses toward iodide ion in a wide concentration range of 1×10-6to 0.1 M with slopes of 58.0±0.8 mV per decade of iodide concentration over a wide pH range of 3-11 with detection limit of detection of ~8×10-7M. The sensors have stable responses times of ≤ 5 s and give stable response after conditioning in 0.05 M KI for 24 h with its response is stable at least 2 months without any considerable divergence in its potential response characteristics. The electrodes were successfully applied for the direct determination of iodide ion in water sample and as indicator electrodes in precipitation titrations.

2010 ◽  
Vol 93 (2) ◽  
pp. 549-555 ◽  
Author(s):  
Gamal Abdel Hafiz Mostafa ◽  
Mohamed Hefnawy ◽  
Abdulrahman Al-Majed

Abstract The construction and electrochemical response characteristics of polyvinylchloride (PVC) membrane sensors for donepezil HCl (DP) are described. The sensing membranes incorporated ion-association complexes of DP cation and sodium tetraphenyl borate (sensor 1), phosphomolybdic acid (sensor 2), or phosphotungstic acid (sensor 3) as electroactive materials. The sensors displayed a fast, stable, and near-Nernstian response over a relatively wide DP concentration range (1 102 to 1 106 M), with cationic slopes of 53.0, 54.0, and 51.0 mV/ concentration decade over a pH range of 4.0 to 8.0. The sensors showed good discrimination of DP from several inorganic and organic compounds. The direct determination of 2.54000.0 g/mL DP showed average recoveries of 99.0, 99.5, and 98.5, and mean RSDs of 1.6, 1.5, and 1.7 at 100.0 g/mL for sensors 1, 2, and 3, respectively. The proposed sensors have been applied for direct determination of DP in two pharmaceutical preparations. The results obtained for determination of DP in tablets using the proposed sensors compared favorably with those obtained using an HPLC method. The sensors have been used as indicator electrodes for potentiometric titration of DP.


Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6375
Author(s):  
Junghwan Kim ◽  
Dae Hee Kim ◽  
Jin Cheol Yang ◽  
Jae Sang Kim ◽  
Ji Ha Lee ◽  
...  

A beryllium(II)-ion-selective poly(ethylenedioxythiophene) (PEDOT) solid contact electrode comprising 9,10-dinitrobenzo-9-crown-3-ether was successfully developed. The all-solid-state contact electrode, with an oxygen-containing cation-sensing membrane combined with an electropolymerized PEDOT layer, exhibited the best response characteristics. The performance of the constructed electrode was evaluated and optimized using potentiometry, conductance measurements, constant-current chronopotentiometry, and electrochemical impedance spectroscopy (EIS). Under optimized conditions, which were found for an ion-selective membrane (ISM) composition of 3% ionophore, 30% polyvinylchloride (PVC), 64% o-nitro phenyl octyl ether (o-NPOE), and 3% sodium tetraphenylborate (NaTPB), the fabricated electrode exhibited a good performance over a wide concentration range (10−2.5–10−7.0 M) and a wide pH range of 2.0–9.0, with a Nernstian slope of 29.5 mV/D for the beryllium (II) ion and a detection limit as low as 10−7.0 M. The developed electrode shows good selectivity for the beryllium(II) ion over alkali, alkaline earth, transition, and heavy metal ions.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Junwei Wang ◽  
Zhiping Du ◽  
Wanxu Wang ◽  
Wei Xue

The construction and characteristic performance of PVC membrane electrode responsive to sodium dodecylsulfate (SDS) are described in this paper. The electrode is based on hexadecyl trimethyl ammonium bromide-Sodium dodecylsulfate (CTA+DS−) ion pair as ionophore in PVC membrane, which displays a Nernstian slope of −58 ± 0.9 mV/decade in a 5.0 × 10−6to 2.5 × 10−3 mol L−1concentration range and a limit of detection of 2.9 × 10−6 mol L−1. The electrode can be used for 3 months without showing significant changes in the value of slope or working range. Also the electrode has wide pH range of application and short response time. The electrode shows a selective response to SDS and a poor response to common inorganic anions. The selective sequence found was SDS > HCO3 −> CH3COO−> Cl−> I−> NO3 −≈Br−> F−> CO3 2−> C6H5O7 3−> C2O4 2−> SO4 2−> C4H4O6 2−> SO3 2−> PO4 3−. The potentiometric selectivity coefficients determined are indicating that common anions would not interfere in the SDS determination. The electrode has been utilized as an end point indicator electrode for potentiometric titration involving hyamine as titrant.


2010 ◽  
Vol 7 (s1) ◽  
pp. S103-S110 ◽  
Author(s):  
Reda Ammar

A novel ritodrine hydrochloride ion-selective PVC membrane electrode based on ion-pair complex of ritodrine-tetra phenyl borate was prepared withdi-n-butyl phosphate as a plasticizer. The influences of membrane composition, temperature, pH of the test solution and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian response over a wide ritodrine concentration range (1×10−5- 1×10−2M) with a slope of 59.33 mV decade−1and was found to be very selective, precise and usable within the pH range 3-7.5. The standard electrode potentials, E°, were determined at different temperatures and used to calculate the isothermal temperature coefficient (dE°/dT) of the electrode, which was 0.00075. The electrode was successfully used for potentiometric determination of ritodrine hydrochloride both in pure solutions and in pharmaceutical preparations.


Author(s):  
YU-HONG TSE ◽  
PAVEL JANDA ◽  
HERMAN LAM ◽  
JIUJUN ZHANG ◽  
WILLIAM J. PIETRO ◽  
...  

The monomeric and polymeric tetra-aminophthalocyane to, cobalt(II) species adsorbed onto graphite electrodes are active in electrocatalytic oxygen reduction. While the monomeric species is unstable, the polymerized species is an effective and stable reduction catalyst over a wide pH range. Both the two-electron reduction of oxygen to hydrogen peroxide and the four-electron reduction of oxygen to water are characterized by cyclic voltammetry, rotating disc and rotating ring-disc studies with appropriate theoretical analysis. Some mechanistic information is obtained. This is the first cobalt phthalocyanine species to provide a four-electron reduction pathway which exists over a wide pH range and is stable. The stability is associated with the polymerization since the monomeric species is not stable.


2016 ◽  
Vol 13 (4) ◽  
pp. 829-837
Author(s):  
Baghdad Science Journal

PVC membrane sensor for the selective determination of Mefenamic acid (MFA) was constructed. The sensor is based on ion association of MFA with Dodecaphospho molybdic acid (PMA) and Dodeca–Tungstophosphoric acid(PTA) as ion pairs. Nitro benzene (NB) and di-butyl phthalate (DBPH) were used as plasticizing agents in PVC matrix membranes. The specification of sensor based on PMA showed a linear response of a concentration range 1.0 × 10–2 –1.0 × 10–5 M, Nernstian slopes of 17.1-18.86 mV/ decade, detection limit of 7 × 10-5 -9.5 × 10 -7M, pH range 3 – 8 , with correlation coefficients lying between 0.9992 and 0.9976, respectively. By using the ionphore based on PTA gives a concentration range of 1.0 × 10–4 –1.0 × 10–5 M, Nernstian slope of 17.18-18.4 mV/ decade, limit of detection 8.0 × 10–6-9.3 × 10-5M,pH range 3 – 8 and correlation coefficients range between 0.9984 and 0.9891, respectively. The measurement interferences in the presence of Li+, Na+, Mg2+ Ca2+, Fe3+and Al3+ were studied using separate and match potential methods for selectivity coefficient determination. The method was applied for the determination of Mefenamic Acid in pharmaceutical preparations


2010 ◽  
Vol 5 (1) ◽  
pp. 73-77
Author(s):  
Mihail Revenco ◽  
Mariana Martin ◽  
Waell Abu Dayyih

A potentiometric selective sensor based on trinuclear chromium(III) complex as a novel ionophore for the thiocyanateselective electrode is reported. The sensor displays a near Nernstian slope of 57 ± 2 mV per decade, over a wide pH range 3 - 11. The working concentration range of the electrode is 1.10-5 – 1.10-1 mol/l with a detection limit of 5.10-6 mol/l. The sensor has a response time of 20 s and can be used for at least 6 months without any considerable fluctuation of the potential. The selectivity coefficients determined at using the fixed interference method indicate a good discriminating ability towards other anions. The prepared sensor was applied as an indicator electrode in the titration of thiocyanate with Ag+.


2011 ◽  
Vol 11 (3) ◽  
pp. 285-289 ◽  
Author(s):  
A. Sentosa Panggabean

Preparation of the chitosan membrane of ion-selective electrode for determination of cadmium ion has been conducted. Chitosan is a natural polymer containing nitrogen could coordinate with Cd2+ to increase the membrane conductivity value. Chitosan is a principal material and mixed with polyvinylchloride (PVC) as matrix dissolved previously to solvent tetrahydrofuran (THF) and dioctylphenylphosphonate (DOPP) is added as plasticizer by proportion chitosan:PVC:DOPP (6:3:1). To obtain the dopant optimum concentration, membrane was dipped in Cd2+ for 7 days and its conductivity value was measured using the four-point probe method. From FT-IR spectrum the peaks of amine, acetylamide and hydroxy groups wavelength number was observed to assure that Cd2+ bound to the chitosan. The optimum concentration of Cd2+ dopant was obtained at 1.00 M with conductivity value of 549.45 ohm-1m-1 wich gave a Nernstian factor of 32.03 mV/decade with the detection limit of 2.512 x 10-5 M. The electrodes work in the pH range 3 - 7. The life time of the electrode was 8 weeks. The ions of Ni2+, Fe3+, Pb2+, Cu2+, Zn2+, Cl- and SO42- toward concentration range 10-3 M gave response did not interfere in the determine of Cd2+ ion.


2019 ◽  
Author(s):  
Guo Li ◽  
Hang Su ◽  
Nan Ma ◽  
Guangjie Zheng ◽  
Uwe Kuhn ◽  
...  

Abstract. Direct measurement of the acidity (pH) of ambient aerosol particles/droplets has long been a challenge for atmospheric scientists. A novel and facile method was introduced recently by Craig et al. (2018), where the pH of size-resolved aerosol droplets was directly measured by two types of pH-indicator papers (pH ranges: 0–2.5 and 2.5–4.5) combined with RGB-based colorimetric analyses using a model of G − B (G minus B) versus pH2. Given the wide pH range of ambient aerosols, we optimize the RGB-based colorimetric analysis on pH papers with a wider detection range (pH ~ 0 to 6). Here, we propose a new model to establish the linear relationship between RGB values and pH: pHpredict = a × Rnormal + b × Gnormal + c × Bnormal. This model shows a wider applicability and higher accuracy than those in previous studies, and is thus recommended in future RGB-based colorimetric analyses on pH papers. Moreover, we identify one type of pH paper (Hydrion® Brilliant pH dip stiks, Lot Nr. 3110, Sigma-Aldrich) that is more applicable for ambient aerosols in terms of its wide pH detection range (0 to 6) and strong anti-interference capacity. The determined minimum sample mass (~ 180 μg) highlights its potential to predict aerosol pH with a high time resolution (e.g., ≤ 1 hour). We further show that the routinely adopted way of using pH color charts to predict aerosol pH may be biased by the mismatch between the standard colors on the color charts and the real colors of investigated samples. Thus, instead of using the producer-provided color chart, we suggest an in-situ calibration of pH papers with standard pH buffers.


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