scholarly journals Liquid membrane ion-selective electrodes for potentiometric dosage of coper and nickel

2005 ◽  
Vol 70 (2) ◽  
pp. 269-276 ◽  
Author(s):  
Maria Pleniceany ◽  
Marian Isvoranu ◽  
Cezar Spinu
Keyword(s):  
Liquid Membrane ◽  
Organic Ligand ◽  
Theoretical Data ◽  
Membrane Electrodes ◽  
Nickel Ions ◽  
Direct Potentiometry ◽  
Graphite Rod ◽  
Active Substances

This paper presents experimental and theoretical data regarding the preparation and characterization of three liquid-membrane electrodes, which have not been mentioned in the specialized literature so far. The active substances, the solutions of which in nitrobenzene formed the membranes on a graphite rod, are simple complex combinations of Cu(II) and Ni(II) ions with an organic ligand belonging to the Schiff base class: N-[2-thienylmethilidene]-2-aminoethanol (TNAHE). The Cu2+ -selective and Ni2+ -selective electrodes were used to determine the copper and nickel ions in aqueous solutions, both by direct potentiometry and by potentiometric titration with EDTA. They were also used for the determination of Cu2+ and Ni2+ ions in industrial waters by direct potentiometry.

scholarly journals Studies on a Pb2+ - selective electrode with a macrocyclic liquid membrane: Potentiometric determination of pb2+ ions

2006 ◽  
Vol 71 (12) ◽  
pp. 1345-1352 ◽  
Author(s):  
Marian Isvoranu ◽  
Constantin Luca ◽  
Maria Pleniceanu ◽  
Cezar Spinu
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Liquid Membrane ◽  
Theoretical Data ◽  
Absorption Spectrometry ◽  
Systematic Errors ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Active Complex ◽  
Direct Potentiometry

This paper presents experimental and theoretical data regarding the design, characterization and analytical applications of a non-expensive, liquid-membrane ion-selective electrode for Pb2+ ions. The membrane is a solution of the active complex formed by Pb2+ ions with dibenzo-18-crown-6-ionophore (DB-[18]-C-6) extracted in propylene carbonate (PC). The successful application of the developed electrode for the determination of Pb2+ ions in aqueos solution samples by direct potentiometry and potentiometric titration is presented. For the presented analytical results, there are insignificant systematic errors between the direct potentiometric method with the developed ion-selective electrode and atomic absorption spectrometry. .

Potentiometric Determination of Non-Ionic Surfactants by Liquid Membrane Electrodes

2003 ◽  
Vol 15 (20) ◽  
pp. 1598-1605 ◽  
Author(s):  
Marco Giannetto ◽  
Claudia Minari ◽  
Giovanni Mori
Keyword(s):  
Liquid Membrane ◽  
Potentiometric Determination ◽  
Ionic Surfactants ◽  
Membrane Electrodes

New Liquid-Membrane Electrodes used for the Determination of Copper and Nickel

1996 ◽  
Vol 29 (9) ◽  
pp. 1485-1496 ◽  
Author(s):  
Maria Pleniceanu ◽  
Mircea Preda ◽  
Nicolae Muresan ◽  
Luminita Simoiu
Keyword(s):  
Liquid Membrane ◽  
Membrane Electrodes ◽  
Determination Of Copper

scholarly journals Analytical applications of electrode sensitive to labetalol in pharmaceuticals

2003 ◽  
Vol 1 (3) ◽  
pp. 242-259 ◽  
Author(s):  
Ewa Gorodkiewicz ◽  
Paweł Falkowski ◽  
Anna Sankiewicz ◽  
Zbigniew Figaszewski
Keyword(s):  
Liquid Membrane ◽  
Inorganic Ions ◽  
Structural Similarity ◽  
Protonated Form ◽  
Direct Potentiometry ◽  
Analytical Properties ◽  
Nernstian Slope ◽  
Ph Range ◽  
Influence Of Ph

AbstractThe analytical properties of an ion-selective electrode sensitive to labetalol with a liquid membrane, based on ion-pair complexes with sodium tetraphenylborate (TPB-Na+) are described. The studied electrode can be used for the determination of labetalol hydrochloride as a protonated form of labetalol in pharmaceuticals. The calibration curve, e.g. EMF=f(pCLabHCl) is linear in the range from 10−5 to 10−2 mol L−1 with a correlation coefficient of 0.9992 and slope of 61.13 mV/decade, which is close to the Nernstian slope. The detection limit of the examined electrode is 7.20×10−6 mol L−1. The influence of pH of the tested solutions on the formulation of the electrode is not as considerable since the electrode works correctly in the pH range 3.0–8.0. The main attributes of the developed electrode are: stability, good reproducibility of EMF and short response time, close to 30 seconds depending on labetalol concentration in the solution. The electrode shows good selectivity for many inorganic ions. The selectivity for drug cations is weaker due to the structural similarity of the interfering cations to labetalol. The results of labetalol determination using direct potentiometry in drugs such as Pressocard (Polpharma) and Trandate (GlaxoWellcome) were compatible with the quantity of labetalol declared by the manufacturer, and with parallel UV spectrophotometric and HPLC determinations.

Development and application of a bioassay to study the effects of nutrients, pH, and active substances on Sordaria macrospora fruiting

1986 ◽  
Vol 32 (12) ◽  
pp. 930-936 ◽  
Author(s):  
Myriam Roure ◽  
Marie-Louise Bouillant
Keyword(s):  
Agaricus Bisporus ◽  
Culture Medium ◽  
Small Variation ◽  
Fruiting Bodies ◽  
Sordaria Macrospora ◽  
Isolation And Characterization ◽  
Initial Ph ◽  
Active Substances

The perithecial development of Sordaria macrospora (Auersw.) is prevented by ammonium salts as nitrogen source, but only below a critical initial pH in the culture medium. Around this point, a very small variation in the initial pH can induce a morpho-genetic change. Within the inhibition range, supplementation of the culture medium with aqueous cell-free extracts from the fruiting mycelia or fruiting bodies of some fungi overcomes the ammonium inhibition. This phenomenon was used to develop a biological test which could be used to isolate, for the determination of their chemical structure, active fungal substances. The precise physiological conditions required to obtain good reproducibility and reliability with this bioassay have been established, which allows the important effects of nutrients and pH on S. macrospora fruiting to be determined. An application is described with the isolation and characterization of hercynine, an active substance purified from Agaricus bisporus fruiting bodies. Its activity is compared with that of other basic substances.

Polyvinyl Chloride Matrix Membrane Electrodes for Manual and Flow Injection Analysis of Chloroquine in Pharmaceutical Preparations

1991 ◽  
Vol 74 (6) ◽  
pp. 900-905 ◽  
Author(s):  
Saad S M Hassan ◽  
Mona A Ahmed
Keyword(s):  
Polyvinyl Chloride ◽  
Flow Injection ◽  
Flow Injection Analysis ◽  
Pharmaceutical Preparations ◽  
Membrane Electrodes ◽  
Direct Potentiometry ◽  
Potentiometric Response ◽  
Ph Range

Abstract Two types of polyvinyl chloride (PVC) matrix membrane electrodes responsive to the antimalarial drug chloroquine have been constructed, electrochemically evaluated, compared, and used in pharmaceutical analysis. Type 1 is the classic PVC model with chloroquine-tetraphenylborate (TPB) sensor; Type 2 is a coated silver disk without internal filling solution. Both electrode types exhibited rapid linear potentiometric response to the logarithmic concentration of diprotonated chloroquine cation in the 10−1–10−6M range with calibration slopes 28-30 mV/concentration decade over the pH range 1.8-6.2. These electrodes were sensitive enough to permit determination of chloroquine phosphate at concentrations as low as 5 μg/mL with good accuracy and precision. Determination of chloroquine in various pharmaceutical preparations using direct potentiometry and potentiometric titration with NaTPB gave an average recovery of 98.8% of the nominal values (SD 0.5%). The Type 2 electrode was also assessed in a flow-through sandwich cell for flow injection analysis. Results were compared with data obtained by the U.S. Pharmacopeia method.

Sign in / Sign up

Export Citation Format

Share Document