scholarly journals Nickel(II) Selective PVC-Based Membrane Sensor Using a Schiff Base

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
B. Rezaei ◽  
H. Hadadzadeh ◽  
A. Azimi

A polyvinylchloride (PVC) membrane optode was prepared by using 1,2-di(o-salicylaldiminophenylthio)ethane (H2DSALPTE) as a chelating reagent for selective determination of Ni(II) ions. The optimized membranes incorporating H2DSALPTE as an ionophore, sodium tetraphenylborate (NaTPB) as an anion excluder, and tributyl phosphate (TBP) as a solvent mediator were prepared and applied for determination of Ni(II) ions. The membrane responded to Ni(II) ion by changing the color from yellow to green in an acetate buffer solution at pH 6.0. The best performance was observed when the membrane having a composition of 3.17% ligand, 31.64% PVC, 63.29% TBP, and 1.90% NaTPB. The membrane can be worked well over a wide concentration range from 1.0 × 10−5 to 5.0 × 10−3 M. The membrane exhibited a detection limit of 8.51 × 10−6 M, and the response time of the membrane was within 7–12 min depending on the concentration of Ni(II) ions. The selectivity of the probe towards nickel determination was found to be very good. Experimental results showed that the probe could be used as an effective tool in analyzing the Ni(II) content of water samples.

2015 ◽  
Vol 7 (16) ◽  
pp. 6791-6798 ◽  
Author(s):  
Anuja Elevathoor Vikraman ◽  
Ammu Rosin Jose ◽  
Meera Jacob ◽  
Krishnapillai Girish Kumar

Thioglycolic acid (TGA) capped CdS quantum dots (QDs) have been successfully employed as an efficient nano sized fluorescent probe for the selective determination of dopamine (DA) in acetate buffer solution (pH 7).


2020 ◽  
Vol 40 (10) ◽  
pp. 842-847
Author(s):  
Shankar Suman ◽  
Ram Singh

AbstractA new poly (vinyl chloride) (PVC) membrane electrode using 2-benzoylpyridine semicarbazone as membrane carrier with dioctylphthalate as plasticizer and sodium tetraphenylborate (NaTBP) as anion excluder has been fabricated and investigated as Zn(II)-selective electrode. Best potential response is observed for the composition PVC 30%, plasticizer 58%, NaTBP 8% and ionophore 4% (w/w). The sensor showed a linear stable response over a concentration range of 1.0 × 10−2–4.56 × 10−6 M with a detection limit of 2.28 × 10−6 M and a response time <10 s. The electrode can be used for at least six months without any divergence in potential.


1950 ◽  
Vol 23 (4) ◽  
pp. 975-980
Author(s):  
F. C. J. Poulton ◽  
L. Tarrant

Abstract Reasons are advanced for the unsatisfactory nature of some of the older methods for the determination of very small amounts of zinc in compounded rubber, particularly in latex mixings. The polarographic technique offers a possible solution, but most of the commoner electrolytes for the electroreduction of this metal are alkaline, and give rise to similar errors as are met in the gravimetric procedure. The development of a suitable acid electrolyte was therefore undertaken, and ways of dealing with likely interferences were examined. The electroltye finally recommended is a potassium thiocyanate-ammonium acetate buffer solution; iron, when present, is reduced to the ferrous condition by potassium iodide. The method was used to determine zinc oxide in a series of mixings of known composition ranging from 0.8 to 40 per cent. In all except the highest proportions of zinc oxide, the figures obtained agree well with the theoretical.


2021 ◽  
Vol 87 (2) ◽  
pp. 19-24
Author(s):  
E. V. Turusova

A rapid method for the determination of Dibazol (bendazol hydrochloride) in liquid and solid dosage forms (DF) has been developed. The method is based on converting the drug into an analytical form and titrating the physiologically active compound (PAC) with a solution of photogenerated iodine obtained by irradiation of an auxiliary solution containing potassium iodide, a mixture of sensitizers (sodium eosinate: fluorescein: auramine, taken in a molar ratio of 1:1:1) and an acetate buffer solution (pH 5.6). A decrease in the titrant content in the cell due to interaction with Dibazol was recorded by a decrease in the current in the amperometric circuit. Stabilization of the current in the circuit indicated the completeness of the reaction, thus providing for estimation of the PAC content in a DF. Further irradiation of the solution and measurement of the generation time required to replenish the titrant loss in the cell also ensure the quantitative estimation of the PAC content in the preparation. The method has been tested on solid dosage form and sterile solutions of Dibazol intended for intramuscular and intravenous administration. A slight effect of stabilizers (hydrochloric acid, ethanol) and auxiliary substances (potato starch) present in the DF on the photogeneration of the titrant was observed. The determined Dibazol content in solid and liquid DF falls within the range recommended by the order of the Ministry of Health of the Russian Federation (26.10.2015 No. 751n) and OFS.1.4.2.0009.15, which indicates that the quality of the drug meets the GMP standards. The linear dependence of the analytical signal on the Dibazol concentration is observed in the range of 13.5 – 134.7 mg for the drug «Dibazol-UBF, tablets, 20 mg». The calculated limits of Dibazol detection and quantitative determination by changes in the current strength and generation time are (4.71; 3.56) and (14.26; 10.77) mg, respectively. The use of developed technique in the analysis of drugs containing Dibazol reduces both the time of single determination due to the absence of the need for standardization of solutions, and the cost of a single analysis, since it does not require the use of expensive equipment and reagents.


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.


Sign in / Sign up

Export Citation Format

Share Document