Adel Shoukry - Academia.edu (original) (raw)

Papers by Adel Shoukry

Research paper thumbnail of Administration of some probiotic strains in the rearing water enhances the water quality, performance, body chemical analysis, antioxidant and immune responses of Nile tilapia, Oreochromis niloticus

Applied Water Science

The performance, efficiency of consumed feed, body chemical composition, survival rate, antioxida... more The performance, efficiency of consumed feed, body chemical composition, survival rate, antioxidant and immunity parameters of Nile tilapia (Oreochromis niloticus) reared in probiotic-treated water were studied. Two hundred apparently healthy Nile tilapia (20 ± 0.3 g) juveniles were reared for 70 days in five different treatments, with five replications as the control group (clean water) and four test groups with two probiotics strains (Bacillus toyonensisandGeobacillus stearothermophilus) at two different levels (1 or 2 × 105 CFU ml−1) applied in rearing water. Fish reared in water supplemented withG. stearothermophilusat low level demonstrated significantly enhanced (p < 0.05) growth performances in terms of final body weight (FBW), weight gain (WG), daily weight gain (DWG), specific growth rate (SGR), and relative growth rate (RGR) compared to the control group. In the same context, supplied fish rearing water a lower amount ofG. stearothermophilus(GS1) remarkedly reduced feed...

Research paper thumbnail of Plastic membrane pOH-electrode based on chlorpromazine base

881-882A new hydroxyl-ion selective poly(vinyl chloride)- membrane electrode based on chlorpromaz... more 881-882A new hydroxyl-ion selective poly(vinyl chloride)- membrane electrode based on chlorpromazine base in the presence of sodium tetraphenyl borate has been prepared with dioctylphthalate as a plasticizer. The performance characteristics of the electrode have been studied. It exhibits a good Nernstian response at room temperature, over a relatively wide range of hydroxyl ion concentrations and is highly selective toward a large number of inorganic anions

Research paper thumbnail of New approach to multiply the sensitivity of direct potentiometry by using two ion-selective electrode-containing cells Application to KCI CuCI2, and CaCI2

Communications, Faculty Of Science, University of Ankara Series B Chemistry and Chemical Engineering, 1993

Research paper thumbnail of Selective Membrane Electrode Potentiometry and Spectrophotometry of a Photochemical Reaction of Thioredazine Hydrochloride

Journal of AOAC INTERNATIONAL, 1988

A PVC membrane electrode of the coated wire type was prepared which is selective for thioredazine... more A PVC membrane electrode of the coated wire type was prepared which is selective for thioredazine. It showed a Nernstian response over a thioredazine concentration range 6.3 x 10 «to 2.5 x 10_3M, at 25°C, and was selective, precise, and usable within the pH range 2.1-7.0. The standard electrode potentials, E°, were determined at different temperatures and used to calculate the isothermal temperature coefficient of the electrode. The photoreaction occurring in thioredazine solution exposed to daylight did not affect the electrode performance. This reaction was investigated kinetically to determine its rate constant and half-life at different temperatures.

Research paper thumbnail of Isolation, Evaluation and Molecular Identification of Streptomyces Isolates with Antimicrobial Activities

Journal of Agricultural Chemistry and Biotechnology, 2019

Out of sixteen Streptomyces sp. isolates were isolated from root rhizosphere soil of tomato plant... more Out of sixteen Streptomyces sp. isolates were isolated from root rhizosphere soil of tomato plants. Four isolates coded; C1, 8SW, 30SW and 11SA were selected as the highest antibiotic productivity. The highest records of the antibiotic productivity were 21 and 25 mm as inhibition zones obtained from the original strains 8SW and 11SA after 10 days using E. coli DH-5α as a tester. The highest records of the antibiotic productivity were 12 mm and 11 mm when used Aspergillus niger and Saccharomyces cerevisiae as testers. Three of the four tested Streptomyces isolates i.e. C1, 8SW and 11SA exhibited highly inhibited (31 mm) of the two fungal plant pathogens. Using RAPD and SRAP marker the clustering of tested isolates were different from each other, RAPD marker could be grouped isolates (C1 and 8SW), (30SW and 11SA) to two clusters. However, SRAP grouped isolates (C1, 8SW and 30SW) in one cluster, however isolate 11SA clustered separately. Based on DNA sequences using 16S rDNA the data showed that isolates C1 and 8SW belonged to Streptomyces albidoflavus and isolates 30SW and 11SA were belonged to Streptomyces bobbili. For more accuracy the isolate C1 aligned with all Streptomyces in gene bank and confirmed in belonged to S. albidoflavus.

Research paper thumbnail of Energy‐Dispersive and X‐Ray Photoelectron Spectroscopy and Electron Microscopy of New Quininium‐Plastic Membrane Electrodes

Annali di Chimica, 2007

New quininium (Qn) plastic membrane electrodes of the conventional type were constructed and char... more New quininium (Qn) plastic membrane electrodes of the conventional type were constructed and characterized. They are based on incorporation of Qn‐reineckate (QnRn) ion‐pair, Qn‐phosphotungstate (Qn3‐PT), or Qn‐phosphomolybdate (Qn3PM) ion associate into a poly(vinyl chloride) membrane. The electrodes are selective for Qn and have been successfully used for the determination of Qn2SO4 in pharmaceutical tablets. Nevertheless, they showed, as almost all other ion‐selective electrodes, limited life times. Energy dispersive‐ (EDS) and X‐ray photoelectron spectroscopy (XPS), as well as electron microscopy were applied to investigate the cause of this limitation in the life times of the electrodes. The results indicated that the electrodes lose their activity after prolonged soaking as a result of leaching of the ion exchanger from the membranes into the test solution in addition to deformation at the surface of the expired electrode.

Research paper thumbnail of Use of two ion-selective electrode-containing cells for potentiometric titration of hexadecylpyridinium bromide

The Analyst, 1988

Page 1. ANALYST, AUGUST 1988, VOL. 113 1305 Use of Two Ion-selective Electrode-containing Cells f... more Page 1. ANALYST, AUGUST 1988, VOL. 113 1305 Use of Two Ion-selective Electrode-containing Cells for Potentiometric Titration of Hexadecylpyridinium Bromide Adel F. Shoukry Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt ...

Research paper thumbnail of Flow injection analysis with tubular membrane ion-selective electrodes in the presence of anionic surfactants

The Analyst, 1983

New Plastic membrane ion-selective electrode for buspirone hydrochloride based on buspironium tet... more New Plastic membrane ion-selective electrode for buspirone hydrochloride based on buspironium tetraphenylborate was prepared. The electrode exhibited mean slope of calibration graph of 58.4 mV per decade of BusCl concentration at 25°C. The electrode can be used within the concentration range 6.3 x10-5-10-2 M BusCl at a pH range of 2.5-7.0. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal temperature coefficient of the electrode, amounting to 0.00056 V°C-1. The electrode showed a very good selectivity for BusCl with respect to a number of inorganic cations, sugars and amino acids. The electrode was applied to the potentiometric determination of the buspirone ion and its pharmaceutical preparation under batch and flow injection conditions. Also, buspirone was determined by conductimetric titrations. Graphite rod, copper and silver coated wire electrodes were prepared and characterized as sensors for the drug under investigation.

Research paper thumbnail of New tetradecyltrimethylammonium-selective electrodes: Surface composition and topography as correlated with electrode's life span

Talanta, 2012

Two conventional plastic membrane electrodes that are selective for the tetradecyltrimethylammoni... more Two conventional plastic membrane electrodes that are selective for the tetradecyltrimethylammonium cation (TTA) have been prepared. The ion exchangers of these sensors were the ion associate, TTA-PT, and the ion aggregate, TTA-PSS, where PT and PSS are phosphotungstate and polystyrene sulfonate, respectively. The following performance characteristics of the TTA-PT-and TTA-PSS-containing electrodes were found: conditioning time of 30 and 20 min; potential response of 58.2 and 61.1 mV/TTA concentration decade; rectilinear concentration ranges of 2.0 × 10 −5-5.0 × 10 −2 and 1.5 × 10 −5-7.9 × 10 −2 mol L −1 ; average working pH ranges of 4.0-10.5 and 3.8-10.7; life spans of 20 and 28 weeks, and isothermal temperature coefficients of 4.44 × 10 −4 and 6.10 × 10 −4 V/ • C, respectively. Both electrodes exhibited high selectivity for TTA with an increasing number of inorganic and quaternary ammonium surfactant cations. These electrodes have been successfully applied to assay an antiseptic formulation containing TTA. Surface analyses using electron microscopy and X-ray photoelectron spectroscopy were used to determine the cause of the limited life span of plastic membrane electrodes.

Research paper thumbnail of Halogen-free ionic liquid as an additive in zinc(II)-selective electrode: Surface analyses as correlated to the membrane activity

Talanta, 2012

Two conventional Zn(II) polyvinyl chloride (PVC) membrane electrodes have been prepared and chara... more Two conventional Zn(II) polyvinyl chloride (PVC) membrane electrodes have been prepared and characterized. They were based on dibenzo-24-crown-8 (DBC) as a neutral carrier, dioctyl phthalate (DOP) as a plasticizer, and potassium tetrakis (p-chlorophenyl) borate, KTpClPB or the halogen-free ionic liquid, tetraoctylammonium dodecylbenzene sulfonate [TOA][DBS] as an additive. The use of ionic liquid has been found to enhance the selectivity of the sensor. For each electrode, the surfaces of two membranes were investigated using X-ray photoelectron, ion-scattering spectroscopy and atomic force microscopy. One of the two membranes was conditioned by soaking it for 24 h in a 1.0 × 10 −3 M Zn(NO 3) 2 solution and the second was soaked in bi-distilled water for the same interval (24 h). Comparing the two surfaces indicated the following: (a) the high selectivity in case of using [TOA][DBS] as an additive is due to the extra mediation caused by the ionic liquid and (b) the working mechanism of the electrode is based on phase equilibrium at the surface of the membrane associated with ion transport through the bulk of the membrane.

Research paper thumbnail of Surface Analyses of Plastic Membrane Copper Ion-Selective Electrodes: Morphological and Spectroscopic Studies of Electrode Activity

Research paper thumbnail of Depth-profiling X-ray photoelectron spectroscopy (XPS) analysis of interlayer diffusion in polyelectrolyte multilayers

Proceedings of the National Academy of Sciences, 2013

Functional organic thin films often demand precise control over the nanometer-level structure. In... more Functional organic thin films often demand precise control over the nanometer-level structure. Interlayer diffusion of materials may destroy this precise structure; therefore, a better understanding of when interlayer diffusion occurs and how to control it is needed. X-ray photoelectron spectroscopy paired with C 60 + cluster ion sputtering enables high-resolution analysis of the atomic composition and chemical state of organic thin films with depth. Using this technique, we explore issues common to the polyelectrolyte multilayer field, such as the competition between hydrogen bonding and electrostatic interactions in multilayers, blocking interlayer diffusion of polymers, the exchange of film components with a surrounding solution, and the extent and kinetics of interlayer diffusion. The diffusion coefficient of chitosan (M = ∼100 kDa) in swollen hydrogen-bonded poly(ethylene oxide)/poly(acrylic acid) multilayer films was examined and determined to be 1.4*10 −12 cm 2 /s. Using the ...

Research paper thumbnail of Potentiometric sensor for phenylephrine based on phenylephrine-tetraphenylborate lipophilic salt

Mikrochimica Acta, 1989

Page 1. Mikrochim. Acta [Wien] 1989, III, 101-108 Mikrochimica Acta 9 by Springer-Verlag 1989 Pot... more Page 1. Mikrochim. Acta [Wien] 1989, III, 101-108 Mikrochimica Acta 9 by Springer-Verlag 1989 Potentiometric Sensor for Phenylephrine Based on Phenylephrine-tetraphenylborate Lipophilic Salt Adel FI Shoukry 1&amp;amp;#x27;*, Ragaa El-Sheikh 2, Yousry M. Issa 1, and Mohsen Zareh 2 ...

Research paper thumbnail of Extraction-spectrophotometric determination of amprolium hydrochloride using bromocresol green, bromophenol blue and bromothymol blue

Mikrochimica Acta, 1997

A new procedure for the determination of amprolium hydrochloride by reaction with bromocresol gre... more A new procedure for the determination of amprolium hydrochloride by reaction with bromocresol green (BCG), bromophenol blue (BPB) and bromothymol blue (BTB) has been developed. The method consists of extracting the yellow ion-pair formed into chloroform from aqueous medium. The ion-pairs have absorption maxima at 420, 410 and 415 nm with molar absorptivities of 3.64 × 104, 3.12 × 104

Research paper thumbnail of Indirect atomic absorption and atomic emission spectrometric determination of antazoline, hydralazine and amiloride hydrochlorides and quinine sulphate

Mikrochimica Acta, 1995

Abstract. Ion-association complexes of antazoline HC1 iI], hydralazine HC1 [II], amiloride HC1 [I... more Abstract. Ion-association complexes of antazoline HC1 iI], hydralazine HC1 [II], amiloride HC1 [III] and quinine sulphate [IV] with leo(SeN)4] 2-and [Co(NO2)6] 3-were precipitated and the excess unreacted cobalt complex was determined. A new method using atomic emission ...

Research paper thumbnail of Reproterol plastic membrane ion-selective electrodes based on its individual and mixed ion-exchangers with phosphotungstic and/or phosphomolybdic acids

Microchemical Journal, 2001

Reproterol hydrochloride RpCl , selective PVC membranes based on ion associates of reproterolium-... more Reproterol hydrochloride RpCl , selective PVC membranes based on ion associates of reproterolium-phos-Ž. Ž. Ž. photungstate Rp-PTA ; reproterolium-phospho-molybdate Rp-PMA or a mixture of both Rp-PTArPMA were prepared. The electrodes displayed a linear response over the concentration range of 6.3= 10 y6 ᎐1.0= 10 y1 mol dm y3 RpCl. The working pH ranges of the above electrodes were 2.5᎐9.0, 2.5᎐8.5 and 2.0᎐9.0 and their isothermal temperature coefficients were 0.00014, 0.00090 and 0.00103 VrЊC, respectively. The electrodes showed good selectivity to the reproterolium ion with respect to many inorganic cations, sugars and amino acids. The standard additions and potentiometric titration methods were used to determine RpCl in pure solutions and in its pharmaceutical preparations with high accuracy and precision.

Research paper thumbnail of Lignocaine ion‐selective electrodes based on its ion‐associates with cobalt thiocyanate, phosphomolybdate and reineckate complex ions

Journal of Chemical Technology & Biotechnology, 1995

Lignocaine (Lg) selective PVC membrane electrodes based on the ionassociates lignocaine‐cobalt th... more Lignocaine (Lg) selective PVC membrane electrodes based on the ionassociates lignocaine‐cobalt thiocynate (I), lignocaine–phosphomolybdate (II) and lingnocaine–reinckate (III) were constructed. The electrodes exhibited linear response over the concentration ranges 0.02–100, 0.01–100 and 0.01–10 mM for I, II and III, respectively. pH did not effect the electrodes performance within the ranges 3–6, 3–7 and 3–6·5 for 10−2, 10−3 and 10−4 M LgHCl, respectively. Interferences are negligible for many inorganic cation, sugars and amino acids. The isothermal coefficients were found to be 0·000459, 0·000698 and 0·000404 V °C−1 for I, II and III, respectively. The life spans of the electrodes are more than 2 months of continuous work. Potentiometric titration and the standard addition method were used to determine LgGCl in pure solutions and in pharmaceutical preparations with high accuracy and precision.

Research paper thumbnail of New plastic membrane ion-selective electrode for determination of trimethoprim

Journal of Chemical Technology AND Biotechnology, 1994

... for Determination of Trimethoprim Mahmoud Aboudan Chemistry Department, Faculty of Science, A... more ... for Determination of Trimethoprim Mahmoud Aboudan Chemistry Department, Faculty of Science, Aleppo University, Aleppo, Syria Yousry M. Issa &amp;amp;amp;amp; Adel F. Shoukry Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt ...

Research paper thumbnail of Plastic Membrane Sensor from a Disposed Combined Glass Electrode. A Project for Graduate and Fourth-Year Undergraduate Students of Analytical Chemistry

Journal of Chemical Education, 2007

Research paper thumbnail of Dipyridamole plastic membrane electrodes based on individual and mixed ion-exchangers of dipyridamolium phosphotungstate and tetraphenylborate

Electroanalysis, 1997

Dipyridamole (Dp) selective PVC mcmbrane based on dipyridamolium phosphotungstate (Dp-PTA). dipyr... more Dipyridamole (Dp) selective PVC mcmbrane based on dipyridamolium phosphotungstate (Dp-PTA). dipyridamolium tetraphenylborate (Dp-TPB) and a mixture of both (Dp-PTA/TPB) were prepared. The electrodes displayed a linear response over the concentration range 6.3 x 1 .0 x lo-' mol dm-3 dipyridamole hydrochloride (DpCI). The working pH ranges of the above electrodes were 2.0-7.5,2.0-7.5 and 2.0-7.0 and their isothermal coefficients were 0.00096,0.00010 and 0.00144 VI'C, respectively. The electrodes showed good selectivity to DpCl with respect to many inorganic cations, sugars and amino acids. Potentiometric titration and standard additions methods were used to determine DpCl in pure solutions and in pharmaceutical preparations with high accuracy and precision.

Research paper thumbnail of Administration of some probiotic strains in the rearing water enhances the water quality, performance, body chemical analysis, antioxidant and immune responses of Nile tilapia, Oreochromis niloticus

Applied Water Science

The performance, efficiency of consumed feed, body chemical composition, survival rate, antioxida... more The performance, efficiency of consumed feed, body chemical composition, survival rate, antioxidant and immunity parameters of Nile tilapia (Oreochromis niloticus) reared in probiotic-treated water were studied. Two hundred apparently healthy Nile tilapia (20 ± 0.3 g) juveniles were reared for 70 days in five different treatments, with five replications as the control group (clean water) and four test groups with two probiotics strains (Bacillus toyonensisandGeobacillus stearothermophilus) at two different levels (1 or 2 × 105 CFU ml−1) applied in rearing water. Fish reared in water supplemented withG. stearothermophilusat low level demonstrated significantly enhanced (p < 0.05) growth performances in terms of final body weight (FBW), weight gain (WG), daily weight gain (DWG), specific growth rate (SGR), and relative growth rate (RGR) compared to the control group. In the same context, supplied fish rearing water a lower amount ofG. stearothermophilus(GS1) remarkedly reduced feed...

Research paper thumbnail of Plastic membrane pOH-electrode based on chlorpromazine base

881-882A new hydroxyl-ion selective poly(vinyl chloride)- membrane electrode based on chlorpromaz... more 881-882A new hydroxyl-ion selective poly(vinyl chloride)- membrane electrode based on chlorpromazine base in the presence of sodium tetraphenyl borate has been prepared with dioctylphthalate as a plasticizer. The performance characteristics of the electrode have been studied. It exhibits a good Nernstian response at room temperature, over a relatively wide range of hydroxyl ion concentrations and is highly selective toward a large number of inorganic anions

Research paper thumbnail of New approach to multiply the sensitivity of direct potentiometry by using two ion-selective electrode-containing cells Application to KCI CuCI2, and CaCI2

Communications, Faculty Of Science, University of Ankara Series B Chemistry and Chemical Engineering, 1993

Research paper thumbnail of Selective Membrane Electrode Potentiometry and Spectrophotometry of a Photochemical Reaction of Thioredazine Hydrochloride

Journal of AOAC INTERNATIONAL, 1988

A PVC membrane electrode of the coated wire type was prepared which is selective for thioredazine... more A PVC membrane electrode of the coated wire type was prepared which is selective for thioredazine. It showed a Nernstian response over a thioredazine concentration range 6.3 x 10 «to 2.5 x 10_3M, at 25°C, and was selective, precise, and usable within the pH range 2.1-7.0. The standard electrode potentials, E°, were determined at different temperatures and used to calculate the isothermal temperature coefficient of the electrode. The photoreaction occurring in thioredazine solution exposed to daylight did not affect the electrode performance. This reaction was investigated kinetically to determine its rate constant and half-life at different temperatures.

Research paper thumbnail of Isolation, Evaluation and Molecular Identification of Streptomyces Isolates with Antimicrobial Activities

Journal of Agricultural Chemistry and Biotechnology, 2019

Out of sixteen Streptomyces sp. isolates were isolated from root rhizosphere soil of tomato plant... more Out of sixteen Streptomyces sp. isolates were isolated from root rhizosphere soil of tomato plants. Four isolates coded; C1, 8SW, 30SW and 11SA were selected as the highest antibiotic productivity. The highest records of the antibiotic productivity were 21 and 25 mm as inhibition zones obtained from the original strains 8SW and 11SA after 10 days using E. coli DH-5α as a tester. The highest records of the antibiotic productivity were 12 mm and 11 mm when used Aspergillus niger and Saccharomyces cerevisiae as testers. Three of the four tested Streptomyces isolates i.e. C1, 8SW and 11SA exhibited highly inhibited (31 mm) of the two fungal plant pathogens. Using RAPD and SRAP marker the clustering of tested isolates were different from each other, RAPD marker could be grouped isolates (C1 and 8SW), (30SW and 11SA) to two clusters. However, SRAP grouped isolates (C1, 8SW and 30SW) in one cluster, however isolate 11SA clustered separately. Based on DNA sequences using 16S rDNA the data showed that isolates C1 and 8SW belonged to Streptomyces albidoflavus and isolates 30SW and 11SA were belonged to Streptomyces bobbili. For more accuracy the isolate C1 aligned with all Streptomyces in gene bank and confirmed in belonged to S. albidoflavus.

Research paper thumbnail of Energy‐Dispersive and X‐Ray Photoelectron Spectroscopy and Electron Microscopy of New Quininium‐Plastic Membrane Electrodes

Annali di Chimica, 2007

New quininium (Qn) plastic membrane electrodes of the conventional type were constructed and char... more New quininium (Qn) plastic membrane electrodes of the conventional type were constructed and characterized. They are based on incorporation of Qn‐reineckate (QnRn) ion‐pair, Qn‐phosphotungstate (Qn3‐PT), or Qn‐phosphomolybdate (Qn3PM) ion associate into a poly(vinyl chloride) membrane. The electrodes are selective for Qn and have been successfully used for the determination of Qn2SO4 in pharmaceutical tablets. Nevertheless, they showed, as almost all other ion‐selective electrodes, limited life times. Energy dispersive‐ (EDS) and X‐ray photoelectron spectroscopy (XPS), as well as electron microscopy were applied to investigate the cause of this limitation in the life times of the electrodes. The results indicated that the electrodes lose their activity after prolonged soaking as a result of leaching of the ion exchanger from the membranes into the test solution in addition to deformation at the surface of the expired electrode.

Research paper thumbnail of Use of two ion-selective electrode-containing cells for potentiometric titration of hexadecylpyridinium bromide

The Analyst, 1988

Page 1. ANALYST, AUGUST 1988, VOL. 113 1305 Use of Two Ion-selective Electrode-containing Cells f... more Page 1. ANALYST, AUGUST 1988, VOL. 113 1305 Use of Two Ion-selective Electrode-containing Cells for Potentiometric Titration of Hexadecylpyridinium Bromide Adel F. Shoukry Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt ...

Research paper thumbnail of Flow injection analysis with tubular membrane ion-selective electrodes in the presence of anionic surfactants

The Analyst, 1983

New Plastic membrane ion-selective electrode for buspirone hydrochloride based on buspironium tet... more New Plastic membrane ion-selective electrode for buspirone hydrochloride based on buspironium tetraphenylborate was prepared. The electrode exhibited mean slope of calibration graph of 58.4 mV per decade of BusCl concentration at 25°C. The electrode can be used within the concentration range 6.3 x10-5-10-2 M BusCl at a pH range of 2.5-7.0. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal temperature coefficient of the electrode, amounting to 0.00056 V°C-1. The electrode showed a very good selectivity for BusCl with respect to a number of inorganic cations, sugars and amino acids. The electrode was applied to the potentiometric determination of the buspirone ion and its pharmaceutical preparation under batch and flow injection conditions. Also, buspirone was determined by conductimetric titrations. Graphite rod, copper and silver coated wire electrodes were prepared and characterized as sensors for the drug under investigation.

Research paper thumbnail of New tetradecyltrimethylammonium-selective electrodes: Surface composition and topography as correlated with electrode's life span

Talanta, 2012

Two conventional plastic membrane electrodes that are selective for the tetradecyltrimethylammoni... more Two conventional plastic membrane electrodes that are selective for the tetradecyltrimethylammonium cation (TTA) have been prepared. The ion exchangers of these sensors were the ion associate, TTA-PT, and the ion aggregate, TTA-PSS, where PT and PSS are phosphotungstate and polystyrene sulfonate, respectively. The following performance characteristics of the TTA-PT-and TTA-PSS-containing electrodes were found: conditioning time of 30 and 20 min; potential response of 58.2 and 61.1 mV/TTA concentration decade; rectilinear concentration ranges of 2.0 × 10 −5-5.0 × 10 −2 and 1.5 × 10 −5-7.9 × 10 −2 mol L −1 ; average working pH ranges of 4.0-10.5 and 3.8-10.7; life spans of 20 and 28 weeks, and isothermal temperature coefficients of 4.44 × 10 −4 and 6.10 × 10 −4 V/ • C, respectively. Both electrodes exhibited high selectivity for TTA with an increasing number of inorganic and quaternary ammonium surfactant cations. These electrodes have been successfully applied to assay an antiseptic formulation containing TTA. Surface analyses using electron microscopy and X-ray photoelectron spectroscopy were used to determine the cause of the limited life span of plastic membrane electrodes.

Research paper thumbnail of Halogen-free ionic liquid as an additive in zinc(II)-selective electrode: Surface analyses as correlated to the membrane activity

Talanta, 2012

Two conventional Zn(II) polyvinyl chloride (PVC) membrane electrodes have been prepared and chara... more Two conventional Zn(II) polyvinyl chloride (PVC) membrane electrodes have been prepared and characterized. They were based on dibenzo-24-crown-8 (DBC) as a neutral carrier, dioctyl phthalate (DOP) as a plasticizer, and potassium tetrakis (p-chlorophenyl) borate, KTpClPB or the halogen-free ionic liquid, tetraoctylammonium dodecylbenzene sulfonate [TOA][DBS] as an additive. The use of ionic liquid has been found to enhance the selectivity of the sensor. For each electrode, the surfaces of two membranes were investigated using X-ray photoelectron, ion-scattering spectroscopy and atomic force microscopy. One of the two membranes was conditioned by soaking it for 24 h in a 1.0 × 10 −3 M Zn(NO 3) 2 solution and the second was soaked in bi-distilled water for the same interval (24 h). Comparing the two surfaces indicated the following: (a) the high selectivity in case of using [TOA][DBS] as an additive is due to the extra mediation caused by the ionic liquid and (b) the working mechanism of the electrode is based on phase equilibrium at the surface of the membrane associated with ion transport through the bulk of the membrane.

Research paper thumbnail of Surface Analyses of Plastic Membrane Copper Ion-Selective Electrodes: Morphological and Spectroscopic Studies of Electrode Activity

Research paper thumbnail of Depth-profiling X-ray photoelectron spectroscopy (XPS) analysis of interlayer diffusion in polyelectrolyte multilayers

Proceedings of the National Academy of Sciences, 2013

Functional organic thin films often demand precise control over the nanometer-level structure. In... more Functional organic thin films often demand precise control over the nanometer-level structure. Interlayer diffusion of materials may destroy this precise structure; therefore, a better understanding of when interlayer diffusion occurs and how to control it is needed. X-ray photoelectron spectroscopy paired with C 60 + cluster ion sputtering enables high-resolution analysis of the atomic composition and chemical state of organic thin films with depth. Using this technique, we explore issues common to the polyelectrolyte multilayer field, such as the competition between hydrogen bonding and electrostatic interactions in multilayers, blocking interlayer diffusion of polymers, the exchange of film components with a surrounding solution, and the extent and kinetics of interlayer diffusion. The diffusion coefficient of chitosan (M = ∼100 kDa) in swollen hydrogen-bonded poly(ethylene oxide)/poly(acrylic acid) multilayer films was examined and determined to be 1.4*10 −12 cm 2 /s. Using the ...

Research paper thumbnail of Potentiometric sensor for phenylephrine based on phenylephrine-tetraphenylborate lipophilic salt

Mikrochimica Acta, 1989

Page 1. Mikrochim. Acta [Wien] 1989, III, 101-108 Mikrochimica Acta 9 by Springer-Verlag 1989 Pot... more Page 1. Mikrochim. Acta [Wien] 1989, III, 101-108 Mikrochimica Acta 9 by Springer-Verlag 1989 Potentiometric Sensor for Phenylephrine Based on Phenylephrine-tetraphenylborate Lipophilic Salt Adel FI Shoukry 1&amp;amp;#x27;*, Ragaa El-Sheikh 2, Yousry M. Issa 1, and Mohsen Zareh 2 ...

Research paper thumbnail of Extraction-spectrophotometric determination of amprolium hydrochloride using bromocresol green, bromophenol blue and bromothymol blue

Mikrochimica Acta, 1997

A new procedure for the determination of amprolium hydrochloride by reaction with bromocresol gre... more A new procedure for the determination of amprolium hydrochloride by reaction with bromocresol green (BCG), bromophenol blue (BPB) and bromothymol blue (BTB) has been developed. The method consists of extracting the yellow ion-pair formed into chloroform from aqueous medium. The ion-pairs have absorption maxima at 420, 410 and 415 nm with molar absorptivities of 3.64 × 104, 3.12 × 104

Research paper thumbnail of Indirect atomic absorption and atomic emission spectrometric determination of antazoline, hydralazine and amiloride hydrochlorides and quinine sulphate

Mikrochimica Acta, 1995

Abstract. Ion-association complexes of antazoline HC1 iI], hydralazine HC1 [II], amiloride HC1 [I... more Abstract. Ion-association complexes of antazoline HC1 iI], hydralazine HC1 [II], amiloride HC1 [III] and quinine sulphate [IV] with leo(SeN)4] 2-and [Co(NO2)6] 3-were precipitated and the excess unreacted cobalt complex was determined. A new method using atomic emission ...

Research paper thumbnail of Reproterol plastic membrane ion-selective electrodes based on its individual and mixed ion-exchangers with phosphotungstic and/or phosphomolybdic acids

Microchemical Journal, 2001

Reproterol hydrochloride RpCl , selective PVC membranes based on ion associates of reproterolium-... more Reproterol hydrochloride RpCl , selective PVC membranes based on ion associates of reproterolium-phos-Ž. Ž. Ž. photungstate Rp-PTA ; reproterolium-phospho-molybdate Rp-PMA or a mixture of both Rp-PTArPMA were prepared. The electrodes displayed a linear response over the concentration range of 6.3= 10 y6 ᎐1.0= 10 y1 mol dm y3 RpCl. The working pH ranges of the above electrodes were 2.5᎐9.0, 2.5᎐8.5 and 2.0᎐9.0 and their isothermal temperature coefficients were 0.00014, 0.00090 and 0.00103 VrЊC, respectively. The electrodes showed good selectivity to the reproterolium ion with respect to many inorganic cations, sugars and amino acids. The standard additions and potentiometric titration methods were used to determine RpCl in pure solutions and in its pharmaceutical preparations with high accuracy and precision.

Research paper thumbnail of Lignocaine ion‐selective electrodes based on its ion‐associates with cobalt thiocyanate, phosphomolybdate and reineckate complex ions

Journal of Chemical Technology & Biotechnology, 1995

Lignocaine (Lg) selective PVC membrane electrodes based on the ionassociates lignocaine‐cobalt th... more Lignocaine (Lg) selective PVC membrane electrodes based on the ionassociates lignocaine‐cobalt thiocynate (I), lignocaine–phosphomolybdate (II) and lingnocaine–reinckate (III) were constructed. The electrodes exhibited linear response over the concentration ranges 0.02–100, 0.01–100 and 0.01–10 mM for I, II and III, respectively. pH did not effect the electrodes performance within the ranges 3–6, 3–7 and 3–6·5 for 10−2, 10−3 and 10−4 M LgHCl, respectively. Interferences are negligible for many inorganic cation, sugars and amino acids. The isothermal coefficients were found to be 0·000459, 0·000698 and 0·000404 V °C−1 for I, II and III, respectively. The life spans of the electrodes are more than 2 months of continuous work. Potentiometric titration and the standard addition method were used to determine LgGCl in pure solutions and in pharmaceutical preparations with high accuracy and precision.

Research paper thumbnail of New plastic membrane ion-selective electrode for determination of trimethoprim

Journal of Chemical Technology AND Biotechnology, 1994

... for Determination of Trimethoprim Mahmoud Aboudan Chemistry Department, Faculty of Science, A... more ... for Determination of Trimethoprim Mahmoud Aboudan Chemistry Department, Faculty of Science, Aleppo University, Aleppo, Syria Yousry M. Issa &amp;amp;amp;amp; Adel F. Shoukry Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt ...

Research paper thumbnail of Plastic Membrane Sensor from a Disposed Combined Glass Electrode. A Project for Graduate and Fourth-Year Undergraduate Students of Analytical Chemistry

Journal of Chemical Education, 2007

Research paper thumbnail of Dipyridamole plastic membrane electrodes based on individual and mixed ion-exchangers of dipyridamolium phosphotungstate and tetraphenylborate

Electroanalysis, 1997

Dipyridamole (Dp) selective PVC mcmbrane based on dipyridamolium phosphotungstate (Dp-PTA). dipyr... more Dipyridamole (Dp) selective PVC mcmbrane based on dipyridamolium phosphotungstate (Dp-PTA). dipyridamolium tetraphenylborate (Dp-TPB) and a mixture of both (Dp-PTA/TPB) were prepared. The electrodes displayed a linear response over the concentration range 6.3 x 1 .0 x lo-' mol dm-3 dipyridamole hydrochloride (DpCI). The working pH ranges of the above electrodes were 2.0-7.5,2.0-7.5 and 2.0-7.0 and their isothermal coefficients were 0.00096,0.00010 and 0.00144 VI'C, respectively. The electrodes showed good selectivity to DpCl with respect to many inorganic cations, sugars and amino acids. Potentiometric titration and standard additions methods were used to determine DpCl in pure solutions and in pharmaceutical preparations with high accuracy and precision.