Potentiometry

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1 - Polymeric Membrane Sensor for Potentiometric Determination of Tin(II) Ions
Hossein Aghaei Masood Giahi Majjid Arvand Mehran Aghaei

Tin(II)-ion-selective electrode consisting of dibenzo-18-crown-6 (DB18C6) as an ionophore inPVC matrix was developed. The influences of membrane composition, selectivity, response time,reversibility and temperature on the electrode performance were investigated. The ele چکیده کامل

Tin(II)-ion-selective electrode consisting of dibenzo-18-crown-6 (DB18C6) as an ionophore inPVC matrix was developed. The influences of membrane composition, selectivity, response time,reversibility and temperature on the electrode performance were investigated. The electrodeshowed a near Nernstian response for Sn2+ ions over a concentration range from 1.0× 10-6 1.0× 10-2 M with a slope of 27.5 ± 0.6 mV per concentration decade in a acidic solution (pH=1). Thelimit of detection was 8.0 × 10-7 M. It has a relatively fast response time and can be used for atleast 3 months without any divergence in potentials. The isothermal temperature coefficient of thiselectrode amounted to 0.0012 V/ °C. The stability constant (log Ks) of the Sn(II) DB18C6complex was determined at 25 °C by potentiometric titration in mixed aqueous solution. پرونده مقاله

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2 - Novel ZrO2 ion-selective electrode based on 4,7,13,16,21,24-hexa oxa- 1,10- diazabicyc1o[8,8,8]-hexa cosane as neutral carrier in PVC matrix
M. Aghaie K. Zare M. Giahi

In this work, a novel Zr02+ PVC-based membrane sensor based on 4,7,13,16,21,24-hexa oxa-1,10- diazabicyclo[8,8,8]- hexa cosane (HODBHC) as a new ionophore is presented. The sensor displays a linear dynamic rangebetween 1.0x 10-1 and 1.0x10 6 M, with a near Nernstian slo چکیده کامل

In this work, a novel Zr02+ PVC-based membrane sensor based on 4,7,13,16,21,24-hexa oxa-1,10- diazabicyclo[8,8,8]- hexa cosane (HODBHC) as a new ionophore is presented. The sensor displays a linear dynamic rangebetween 1.0x 10-1 and 1.0x10 6 M, with a near Nernstian slope of 29.9 ± 0.4 mV per decade in an acidic solution(pH=1). The limit of detection is 8.0 x 1 0 7 M. The electrodes possess advantages of low resistance, very fastresponse time, relatively long lifetimes and, especially, good selectivities relative to a wide variety of othercations. It was used as indicator electrode in potentiometric determination of ZrO2+ ion by standard additionmethod at pH 1.0 in two samples. پرونده مقاله

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3 - Comparison of the vanadyl-selective electrodes prepared by sol–gel and PVC membrane techniques
Masoud Giahi Mohammad Ali Bagherinia Azin Azari

Sol-gel and polymeric membrane electrodes, based on thiacalix[4]arene as a neutral carrier, weresuccessfully developed for the detection of VO2+ in aqueous solutions. The sol-gel and PVCmembrane electrodes exhibited linear response with Nernstian slopes of 29.3 and 28.4 چکیده کامل

Sol-gel and polymeric membrane electrodes, based on thiacalix[4]arene as a neutral carrier, weresuccessfully developed for the detection of VO2+ in aqueous solutions. The sol-gel and PVCmembrane electrodes exhibited linear response with Nernstian slopes of 29.3 and 28.4 mV perdecade, respectively, within the vanadyl ion concentration ranges from 1.0 × 10-6 to 1.0 × 10-1mol dm-3 and from 1.0 × 10-5 to 1.0 × 10-1 mol dm-3 for sol-gel and PVC membrane sensors.The PVC-based and sol-gel electrodes show detection limits of 3.1 × 10-6 and 4.9 × 10-7 mol dm-3, respectively, and also response time of about 15 s to achieve a 95% steady potential for VO2+concentration. By testing the stability lifetimes of the electrodes over a six-month period, nosignificant change was observed in the performance of the sol-gel electrode, however, the PVCbasedvanadyl-selective electrode exhibited a gradual decrease in the slope after two months.Investigating the influence of membrane composition, the pH of the test solution, and theinterfering ions on the electrodes performance revealed good selectivity of electrodes for a numberof alkali, alkaline earth, transition and heavy metal ions. The determined isothermal temperaturecoefficients of these electrodes showed a better thermal stability of sol-gel electrode rather thanthat of the PVC-based vanadyl-selective electrode, however, the electrodes performance isdeteriorated by temperatures higher than 50 °C. پرونده مقاله

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4 - Sn (II) Ion- Selective Membrane Electrode based on Dibenzo-18-Crown-6
H. Aghaie M. Giahi1 Giahi M. Aghaei M. Arvand3

We found that dibenzo-18-crown-6 (DB18C6) can be used as an ionophore to make a tin (II)-ionselectivemembrane electrode. The electrode exhibits a near Nernstian response for Sn2+ ions over aconcentration range from 1.0× 10-6 1.0× 10-2 M with a slope of 27.5 چکیده کامل

We found that dibenzo-18-crown-6 (DB18C6) can be used as an ionophore to make a tin (II)-ionselectivemembrane electrode. The electrode exhibits a near Nernstian response for Sn2+ ions over aconcentration range from 1.0× 10-6 1.0× 10-2 M with a slope of 27.5 ± 0.6 mV per concentration decadein an acidic solution (pH=1). The limit of detection was 8.0× 10-7 M. It has a response time of < 20s andcan be used for at least 3 months without any divergence in potentials. The proposed membrane electroderevealed very good selectivity for Sn2+ ions over a wide variety of other cations and could be used inacidic media. It was used as indicator electrode in potentiometric determination of tin (II) ion in realsample. پرونده مقاله

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5 - Manganese (M-selective PVC membrane electrode based on N-(2- picolinamido ethyl)-Picolinamide as ionophore
M. Zawari M. Giahi H. Aghaie

In this research, a PVC membrane electrode for Manganese (II) ions based on N-(2-Picolinamidoethyl)Picolinamide as neutral carrier was prepared. The electrode exhibits a Nemstian responseover Mn(II) concentration range of (1.0 x10-5 t01.0 X 10-1M) with a slope of 29.3&p چکیده کامل

In this research, a PVC membrane electrode for Manganese (II) ions based on N-(2-Picolinamidoethyl)Picolinamide as neutral carrier was prepared. The electrode exhibits a Nemstian responseover Mn(II) concentration range of (1.0 x10-5 t01.0 X 10-1M) with a slope of 29.3±0.5 mV perdecade of concentration with a working pH range of 4.0-9.0. It has a fast response time (<15s) andcan be used for at least two months without any considerable divergence in the potential. Theproposed sensor shows a fairly good discriminating ability towards Mn2+ ion in comparison tosome hard and soft metal ions. Selectivity coefficients determined by the matched potentialmethod (MPM). The electrode was applied to the determination of Manganese (II) ions in realsamples. پرونده مقاله

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6 - Preparation and Application of Al3+ - Sensor Based On (2Z) — Methyl 2 — ((z) (p-tolylimino) -3-Ethyl —4-0xothiazolidin —5— Ylidene Acetate in PVC Matrix
J. Mofidi A. Islamnezhad F. Pour Hojat

Al3+-Potentiometric sensor, based on (2Z) -methyl 2- ((z) (p-tolylimino)-3-ethyl -4-oxothiazolidin -5- ylidene) Acetate (MTEOY) as a neutral ionophore, was successfully developed for the detectionof Al3+ in aqueous solutions. The electrode responds to Al3+ ion with a se چکیده کامل

Al3+-Potentiometric sensor, based on (2Z) -methyl 2- ((z) (p-tolylimino)-3-ethyl -4-oxothiazolidin -5- ylidene) Acetate (MTEOY) as a neutral ionophore, was successfully developed for the detectionof Al3+ in aqueous solutions. The electrode responds to Al3+ ion with a sensitivity of 19.8 ± 0.1 mV/decade over the range 1.0 x 10-8- 1.0 x 10-1 mol LT' and in a pH range of 3.0-9.0. The electrodeshows a detection limit of 3.5 x 10 mo1 U'. The influence of membrane composition, the pH of thetest solution, and the interfering ions on the electrode performance was investigated. The proposedelectrode shows good discrimination of Al3+ ion from several cations. The effect of temperature onthe electrode response shows that the temperature higher than 50 °C deteriorates the electrodeperformance. The electrode was found to work well under laboratory conditions. This sensor not onlywas used in determination of AV. i n real samples but also was used to determination of Ali'concentration in the presence of certain interfering ions. پرونده مقاله

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7 - N-phenylaza-15-crown-5 as Ionophore in PVC-Matrix for Fe2+ - Selective Sensor
M. Aghaie M. Giahi H. Aghaie M. Pournaghdy

The preparation of polymer membrane selective to Iron(II) ion and its application to ion-selectiveelectrode is reported here. PVC membrane contains Ironselective N-phenylaza-15-crown-5 asionophore. The membrane electrode is highly selective to Iron(II) ion and exhibit g چکیده کامل

The preparation of polymer membrane selective to Iron(II) ion and its application to ion-selectiveelectrode is reported here. PVC membrane contains Ironselective N-phenylaza-15-crown-5 asionophore. The membrane electrode is highly selective to Iron(II) ion and exhibit good linearresponse over a wide concentration range of 1.0 × 10-2 to 1.0 × 10-6 M with Nernstian slope of29.2 ± 0.6 mV per decade. The detection limit of electrode is 2.5×10-6 M. It has a response time of<15 s and can be used for more than 2 months without any measurable divergence in potential.The proposed sensor shows fairly a good discriminating ability towards Fe2+ ion in comparison tosome hard and soft metals. The electrode was applied to the determination of Fe2+ ions in theferrous sulfate syrup. پرونده مقاله

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8 - Cu(II) Ion- Selective Membrane Electrode Based on bis(N-salicylidene-3,3'-diamino diphenyl) sulfone
M. Aghaie M. H. Fekri M. Giahi E. Baghdar S. Farhadi

In order to study the Cu(II) ion selective electrode, an optimized membrane was prepared by mixing of 30 mg of PVC powdered, 5 mg of considered ionophore, 60 mg of plasticizer and 5 mg of additive. The sensor showed a near Nernstian response for Cu(II) ions over a conce چکیده کامل

In order to study the Cu(II) ion selective electrode, an optimized membrane was prepared by mixing of 30 mg of PVC powdered, 5 mg of considered ionophore, 60 mg of plasticizer and 5 mg of additive. The sensor showed a near Nernstian response for Cu(II) ions over a concentration range from 1.0×0-6 1.0×0-2 M with a slope of 28.90.5 mV per concentration decade with a working pH range of 3.5-6.3. The limit of detection was 1.010-6 M. The response time of the electrode is about 15s and can be used for more than 2 month without any divergence in potential. The proposed sensor showed fairly a good discriminating ability towards Cu(II) ion in comparison to other ions. The practical application of the electrode was tested by using it as an indicator electrode to determine the end point in the potentiometric titration of Cu(II) with EDTA solution. پرونده مقاله

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9 - Solvent Effect on Protonation Constants of L-alanine and Alanine Methyl ester in Different Aqueous Solutions of 1,4-Dioxane
Mehry Seyed Mojarad Somaryn Farrokh Gharib

The protonation constants of alanine and alanine methyl ester were determined in different aqueous solutions of 1,4-dioxane containing (0-50% v/v), using a potentiometric method at 25o C and constant ionic strength 0.1 mol.L-1 (NaCl). The protonation constants were anal چکیده کامل

The protonation constants of alanine and alanine methyl ester were determined in different aqueous solutions of 1,4-dioxane containing (0-50% v/v), using a potentiometric method at 25o C and constant ionic strength 0.1 mol.L-1 (NaCl). The protonation constants were analyzed in terms of Kamlet, Abboud and Taft (KAT) parameters. The results show that the effect of β is higher in comparison with the other parameters (α and π*). Single-parameter correlation of the constants versus α, β, and π* are poor in all solutions. But multi-parameter correlation represents significant improvements with regard to the single- parameter models. پرونده مقاله

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10 - Determination of Cobalt(II) by a New PVC Membrane Coated Graphite Electrode Based on 6-chloro-11- azabenzo[a]phenothiazin-5-one as a neutral ion carrier
Mohammad Reza Jalali Sarvestani Roya Ahmadi

Cobalt has great biological effects on human beings and also other living organisms, hence its determination is very important. In this regard, a novel coated graphite electrode was designed for determination of Co2+ ions by exploiting 6-chloro-11- azabenzo[a]phenothiaz چکیده کامل

Cobalt has great biological effects on human beings and also other living organisms, hence its determination is very important. In this regard, a novel coated graphite electrode was designed for determination of Co2+ ions by exploiting 6-chloro-11- azabenzo[a]phenothiazin-5-one as a neutral ion carrier, for the first time. The foremost function was witnessed from the membrane composition of PVC (29%), Potassium tetrakis (4-chlorophenyl) borate (2%) as an ionic additive,6-chloro-11-azabenzo[a]phenothiazin-5-one (9%) as ionophore and Dioctylphthalate (60%) as Plasticizer. The linearity domain of the membrane sensor was from 5×10-7 to 1×10-2 Mol L-1 with the Nernstian slope value of 30.1 mV.Decade-1. The potential response of the designed electrode was also investigated in non-aqueous mediums and it was found out that the electrode is also able to be used in systems that are entailed of 20% of ethanol and acetone organic solvents. The response time and lifespan of the electrode was 5 S and 3 months respectively. The sensor selectivity was also evaluated by match potential method over other cations and it shows an eminent selectivity towards Co2+ over all of the inspected ions. The applicability of the electrode in the potentiometric titration with EDTA was also investigated. In the end, the proposed electrode was utilized for determination of Co2+ in four aqueous specimens as real samples. پرونده مقاله

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11 - Design and preparation of Magnesium (II) selective electrode based on novel synthetic ligand and optimization by D-optimal method
Ahmad Adeli Razieh Sanavi Khoshnood S.Ali Beyramabadi Mehdi Pordel Ali Morsalia

The utility of carbon as the base material for carbon paste electrodes has been considered for many years. In this work, we were applied MWCNT as a modifier and Schiff base chitosan and 5-nitro isatin as ionophore along with carbon. Prepared CPE shows a Nernstian respon چکیده کامل

The utility of carbon as the base material for carbon paste electrodes has been considered for many years. In this work, we were applied MWCNT as a modifier and Schiff base chitosan and 5-nitro isatin as ionophore along with carbon. Prepared CPE shows a Nernstian response of 29.567 mV per decade in a wide linear dynamic range of 1.0 × 10-5 to 1.0 ×10-1 M for Mg2+ ion. The optimization process had performed by Mixture design in design expert software. This present sensor has a short time of response of about 10 s. The applicable pH range was obtained 3.51-9.0 and Detection limit was calculated 1.4 ×10-5 M. Lastly, the prepared sensor was used in the indirect potentiometry (potentiometric titration) as an indicator or working electrode. The data obtained from the experiments showed that the electrode is usable in analytical applications. پرونده مقاله

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12 - New Coated Graphite Potentiometric Sensor for Selective Determination of Copper (II) Ions
Arezoo Ghaemi Zahra Setareh

A highly selective copper (II) coated graphite sensor was prepared by 1,13-bis(8-quinolyl)- 1,4,7,10,13-pentaoxatridecane (kryptofix 5) as a supramolecule ionophore into plasticized polyvinyl chloride (PVC) membrane. The best response characteristic was observed using t چکیده کامل

A highly selective copper (II) coated graphite sensor was prepared by 1,13-bis(8-quinolyl)- 1,4,7,10,13-pentaoxatridecane (kryptofix 5) as a supramolecule ionophore into plasticized polyvinyl chloride (PVC) membrane. The best response characteristic was observed using the membrane composition of PVC = 30.0 mg, dioctyl sebacate (DOS) = 63.5 mg, palmitic acid (PA) = 3.0 mg and kryptofix 5 = 3.5 mg. The sensor exhibits a nernstian slope (30.0±0.2 mV/ decade) in a wide linear concentration range of 1.0×10-5 to 1.0×10-1 M with detection limit of 8.7×10-6 M. The electrode has a fast response time of 15 s with a satisfactory reproducibility and relatively long life time of about 16 weeks without significant drift in potential. The sensor operates in the wide pH range of 2.0-10.0. This sensor reveals a good selectivity towards Cu2+ ion over a wide range of alkali, transition and heavy metal cations. The electrode was used as an indicator electrode for potentiometric titration of Cu2+ using EDTA solutions. The proposed sensor was applied for the direct determination of Cu2+ cation and the results were compared with those obtained from atomic absorption spectrometric analysis and were found in good agreement. Also this sensor was successfully used for determination of copper (II) in real samples پرونده مقاله

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13 - Quantitative monitoring of chromium (III) by a selective sensor based on dibenzo-18-crown-6 as a neutral ion carrier
Maryam Alaie Arezoo Ghaemi

In present study a chromium (III) selective sensor based on dibenzo-18-crown-6 as a macrocyclic ionophore was fabricated. The best operation obtained in the membrane including: 5.0 mg dibenzo-18-crown-6 (DB-18C6), 4.0 mg sodium tetraphenylborate (NaTPB), 61.0 mg dioctyl چکیده کامل

In present study a chromium (III) selective sensor based on dibenzo-18-crown-6 as a macrocyclic ionophore was fabricated. The best operation obtained in the membrane including: 5.0 mg dibenzo-18-crown-6 (DB-18C6), 4.0 mg sodium tetraphenylborate (NaTPB), 61.0 mg dioctyl sabacate (DOS) and 30.0 mg polyvinyl chloride (PVC). This electrode has a good selectivity respect to Cr3+ cation, with a nernstian slope of 19.6±0.1 mV/decade in a linear concentration range of 1.0×10-5 M-1.0×10-1 M. The detection limit of the electrode is 8.8×10-6 M. The porposed sensor has a fast response time of 5 s and good reproducibility. It can be used for a period of 63 days without any significant changes in its potential. The effects of the pH and possible interfering ions were investigated. This electrode was employed as an indicator electrode in potentiometric titrations of chromium cation with EDTA solutions and a sharp break in titration curves around the equivalent point was observed. This sensor was successfully used for the determination of chromium (III) in real samples. پرونده مقاله

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14 - A novel sensor based on a heterocyclic ionophore for cerium (III) analysis in real samples
Arezoo Ghaemi Haman Tavakkoli Fariba Mehranfar

A new polyvinyl choloride (PVC) membrane sensor for cerium(III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensorexhibites a linear concentration range of 1.0×10-6 to 1.0×10-1 M, with چکیده کامل

A new polyvinyl choloride (PVC) membrane sensor for cerium(III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensorexhibites a linear concentration range of 1.0×10-6 to 1.0×10-1 M, with aNernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7M. It has a fast response time (5 s) and can be used for two monthswithout any considerable divergence in its potential. The proposedsensor revealed high selectivity toward Ce3+ ion with respect to somealkali, alkaline earth and transition metal cations. It could be used in awide pH range of 2.0-11.0. The sensor was successfully used as anindicator electrode in potentiometric titration of Ce3+ ion withethylenediaminetetraacetic acid (EDTA) and sodium iodide (NaI)solutions, and in determination of Ce (III) concentration in real samples. پرونده مقاله

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15 - Highly selective and sensitive sensor based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane as a heterocyclic ionophore
Fariba Mehranfar Arezoo Ghaemi Haman Tavakkoli

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6to 1.0×10-1M, with چکیده کامل

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6to 1.0×10-1M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7M. It has a fast response time (5 s) and can be used for two months without any considerable divergence in its potential. The proposed sensor revealed high selectivity toward Ce3+ion with respect to some alkali, alkaline earth and transition metal cations. It could be used in a wide pH range of 2.0-11.0. The sensor was successfully used as an indicator electrode in potentiometric titration of Ce3+ion with ethylenediaminetetraacetic acid (EDTA) and sodium iodide (NaI) solutions, and in determination of Ce (III) concentration in real samples. پرونده مقاله

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16 - A novel sensor based on a heterocyclic ionophore for cerium (III) analysis in real samples
Arezoo Ghaemi Haman Tavakkoli Fariba Mehranfar

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6 to 1.0×10-1 M, wit چکیده کامل

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6 to 1.0×10-1 M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7 M. It has a fast response time (5 s) and can be used for two months without any considerable divergence in its potential. The proposed sensor revealed high selectivity toward Ce3+ ion with respect to some alkali, alkaline earth and transition metal cations. It could be used in a wide pH range of 2.0-11.0. The sensor was successfully used as an indicator electrode in potentiometric titration of Ce3+ ion with ethylenediaminetetraacetic acid (EDTA) and sodium iodide (NaI) solutions, and in determination of Ce (III) concentration in real samples پرونده مقاله

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17 - Calcium measurement using ion selective electrode based on a benzo-18-crown-6 as an ionophore
Shaghayegh Lovineh Arezoo Ghaemi

A new PVC based membrane using benzo-18-crown-6 as an ionophore has been developed as a calcium ion selective electrode. The electrode comprises of ionophore (4%), PVC (30%) and plasticizer (63%). The electrode shows a linear dynamic response in the concentration range چکیده کامل

A new PVC based membrane using benzo-18-crown-6 as an ionophore has been developed as a calcium ion selective electrode. The electrode comprises of ionophore (4%), PVC (30%) and plasticizer (63%). The electrode shows a linear dynamic response in the concentration range of 1×10−5 M to 1×10−1 M with a Nernstian slope of 29.8 mV/decade and detection limit is 4.0×10−6 M. The proposed sensor shows reasonably good selectivity with respect to alkali, alkaline earth and transition metal ions. It can be used in the pH range of 5 to 12. The proposed electrode also was applied for the direct determination of Ca2+ cation in doubly distilled deionized water samples spiked with different concentrations of calcium. This electrode was also used for determination of Ca2+ in real samples with a very good recovery. پرونده مقاله

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18 - Novel ZrO2+ Ion-selective Electrode Based on a Hexa Cosine Compound in PVC Matrix
مسعود گیاهی خورشید مهدی زاده نیلوفر رفیع زاده زعیم

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19 - An electrode immobilized in a graphite matrix with ion pair complex for the determination of diclofenac in pharmaceuticals
Zholt Kormosh Iryna Hunka Yaroslav Bazel

A simple, precise, rapid and low-cost potentiometric method for diclofenac determination in pharmaceuticals is proposed. A new diclofenac-sensitive electrode was constructed by incorporating the diclofenac ion pair complex with butyl rhodamine B into graphite matrix. Th چکیده کامل

A simple, precise, rapid and low-cost potentiometric method for diclofenac determination in pharmaceuticals is proposed. A new diclofenac-sensitive electrode was constructed by incorporating the diclofenac ion pair complex with butyl rhodamine B into graphite matrix. The electrode exhibited a linear response over the concentration range of 1 × 10-4 – 5 × 10-2 mol L-1, a detection limit of 3.9×10-5 mol L-1 with a Nernstian slope of 61 ± 2 mV decade-1. The working pH range is 6-11. The electrode is easily constructed, has fast response time (3-11 s) and can be used for the period of six months without any considerable deterioration. The proposed sensor displays good sensitivity for diclofenac in the presence of several substances. It was used to assay diclofenac in pharmaceuticals. پرونده مقاله

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20 - Iodide selective membrane electrode based on copper (Π)-bis-Nphenilsalicyldenaminato complex
Ali Benvidi Mehdi Elahizadeh Hamid Reza Zare, Rasoul Vafazadeh

An iodide ion-selective PVC membrane sensor based on copper (Π)-bis-Nphenilsalicyldenaminatocomplex as a novel sensing material is successfully developed. Theelectrode showed a good selectivity for iodide ion with respect to common inorganic anions. Thesensor exhibit چکیده کامل

An iodide ion-selective PVC membrane sensor based on copper (Π)-bis-Nphenilsalicyldenaminatocomplex as a novel sensing material is successfully developed. Theelectrode showed a good selectivity for iodide ion with respect to common inorganic anions. Thesensor exhibited a good linear response with slope of _58.6 ± 0.4 mV per decade over theconcentration range of 5.0 × 10-6 to 1.0 × 10-1 mol L-1, and a detection limit of 3.0 × 10-6 mol L-1of I– ion. The electrode response was independent of pH in the range of 3.0 - 10.0. The proposedsensor was applied as an indicator electrode in potentiometric titration of I– with Ag+ ion, and todetermine the iodide in sodium chloride salt. پرونده مقاله

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21 - Study of protonation equilibrium of lorazepam by potentiometry and multiwavelengths spectrophotometry
Ateesa Yazdanipour

The acid-base equilibrium of lorazepam was studied by means of potentiometry andmultiwavelengths spectrophotometry. The stoichiometric equilibrium constants were determinedat 25 °C and constant ionic strength 0.1 mol L-1 (NaCl). The acidity constants pK1=1.58&plusmn چکیده کامل

The acid-base equilibrium of lorazepam was studied by means of potentiometry andmultiwavelengths spectrophotometry. The stoichiometric equilibrium constants were determinedat 25 °C and constant ionic strength 0.1 mol L-1 (NaCl). The acidity constants pK1=1.58±0.05and pK2=11.67±0.07 were found by potentiometry, and pK1=1.54±0.02 and pK2=11.61±0.03 bymulti-wavelengths spectrophotometry. Potentiometric determination of equilibrium constantswas performed by application of the formation function method. Data analysis program appliedfor multi-wavelengths spectrophotometric determination of acidity constants. پرونده مقاله

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