共查询到20条相似文献,搜索用时 170 毫秒
1.
M. R. Ganjali P. Norouzi R. Dinarvand F. Faribod A. Moghimi 《Journal of Analytical Chemistry》2008,63(7):684-689
In this work, for the first time, we introduce a highly selective and sensitive Be(II) microsensor. 4-nitrobenzo-9-crown-3-ether
(NBCE) was used as a membrane-active component to prepare a Be(II)-selective polymeric membrane microelectrode. The electrode
exhibits a Nernstian response toward Be(II) ions over a very wide concentration range (1.0 × 10−4–1.0 × 10−10 M), with a detection limit of 3.5 × 10−11 M (∼350 pg/L). In fact, the electrode presents a fast response time in the whole concentration range (6 s). The proposed
microelectrode can be used for at least six weeks without any considerable divergence in the potentials. The proposed membrane
sensor revealed a selectivity toward Be(II) ions over a wide variety of other metal ions including common alkali, alkaline-earth,
and rare-earth ions. It could be used in the pH range of 3.0–11.5. The microelectrode was successfully used as an indicator
electrode for the titration of 20 mL of 1.0 × 10−6 M Be2+ solution with 1.0 × 10−4 M of EDTA. It was also applied to the direct determination of beryllium ions in beryl and binary mixtures.
The text was submitted by the authors in English. 相似文献
2.
A new poly(vinyl chloride)-based membrane was fabricated with the cobalt(II) complex of 2,4-dimethyl-1,5,8,11-tetraazacyclotrideca-1,4-diene
[Me2(13)dieneN4] as an ion carrier. The membrane composition was Co2+ complex/PVC/NaTPB/DBP 15:50:15:20 (w/w). The sensor exhibited a Nernstian response for Co2+ ions over a wide concentration range (7.94×10−6–1.0×10−1 M) at pH 2.5–7.0, a response time of 10 s, and it could be used for 3 months without any significant divergence in potential.
The proposed membrane sensor exhibited good selectivity for Co2+ over a wide variety of other metal ions and in mixtures containing up to 25% (v/v) non-aqueous content. The sensor was successfully
used as an indicator electrode in the potentiometric titration of Co2+ with EDTA and the direct determination of Co2+ in real samples. 相似文献
3.
H. A. Zamani G. Rajabzadeh A. Firouz M. R. Ganjali 《Journal of Analytical Chemistry》2007,62(11):1080-1087
A PVC membrane containing 4-amino-6-methyl-1,2,4-triazin-3,5-dithione (AMTD) as a suitable ionophore, exhibits a Nernstian
response for Cu2+ ions over a wide concentration range up to 1 × 10−1 and 1 × 10−6 M, with a detection limit of 7.5 × 10−7 M in the pH range 3.0–7.5. It has a fast response time (<15 s) and can be used for at least 12 weeks without any major deviation
in the potential. The electrode revealed a very good selectivity with respect to all common alkali, alkaline-earth, transition,
and heavy-metal ions. It was successfully applied to the recovery of copper ions from wastewater. The electrode was also used
as an indicator electrode in the potentiometric titration of Cu(II) ions with EDTA.
The text was submitted by the authors in English. 相似文献
4.
Cecylia Wardak 《Central European Journal of Chemistry》2008,6(4):607-612
A new all plastic sensor for Co2+ ions based on 2-amino-5 (hydroxynaphtyloazo-1′)-1,3,4 thiadiazole (ATIDAN) as ionophore was prepared. The electrode exhibits
a low detection limit of 1.5 × 10−6 mol L−1 and almost theoretical Nernstian slope in the activity range 4.0 × 10−6–1 × 10−1 mol L−1 of cobalt ions. The response time of the sensor is less than 10 s and it can be used over a period of 6 months without any
measurable divergence in potential. The proposed sensor shows a fairly good selectivity for Co(II) over other metal ions.
The electrode was successfully applied for determination of Co2+ in real samples and as an indicator electrode in potentiometric titration of Co2+ ions with EDTA.
相似文献
5.
A Pt wire coated with a bentonite–carbon composite in a poly(vinyl chloride) membrane was used for detection of lead. The
sensor has a Nernstian slope of 29.42±0.50 mV per decade over a wide range of concentration, 1.0×10−7 to 1.0×10−3 mol L−1 Pb(NO3)2. The detection limit is 5.0×10−8 mol L−1 Pb(NO3)2 and the electrode is applicable in the pH range 3.0–6.7. It has a response time of approximately 10 s and can be used at
least for three months. The electrode has good selectivity relative to nineteen other metal ions. The practical analytical
utility of the electrode is demonstrated by measurement of Pb(II) in industrial waste and river water samples. 相似文献
6.
Ajay Kumar Jain Raj Kumar Singh Shalabh Jain Jitendra Raisoni 《Transition Metal Chemistry》2008,33(2):243-249
A new Cu (II) ion-selective electrode has been fabricated in poly (vinyl chloride) matrix based on a recently synthesized
Schiff-base chelate. The addition of sodium tetraphenylborate (NaTPB) and various plasticizers viz. TBP, TEHP, DOS, and CN
have been found to substantially improve the performance of the electrode. The membrane of various compositions of the ionophore
(I) were investigated and it was found that the best performance was obtained with the membrane having (I): PVC: NaTPB: CN
in the ratio 4: 140: 3: 80 (mg). The electrode exhibits a Nernstian response over a wide concentration range (1.9 × 10−6–1.0 × 10−1 M) with 30.0 mV/decade of concentration between pH 3.0 and 7.5. The response time of the electrode is about 12 s and it can
be used over a period of 3 months without any divergence in potential. The potentiometric selectivity coefficient values as
determined by fixed interference method indicate excellent selectivity for Cu2+ ions over interfering cations. The electrode has also been used successfully in partially non-aqueous media having a 25%
(v/v) methanol, ethanol or acetone content without showing any considerable change in the value of slope or working concentration
range. The electrode has been used in the potentiometric titration of Cu2+ with EDTA. 相似文献
7.
Irena Grabec vegl Mitja Kolar Boidar Ogorevc Boris Pihlar 《Fresenius' Journal of Analytical Chemistry》1998,361(4):358-362
A vermiculite modified carbon paste electrode (VMCPE) was employed for the in situ preconcentration of traces of Hg(II)
and Ag(I) via an ion-exchange route. Heavy metal ions were accumulated in Britton-Robinson (BR) buffer pH 7 for Hg(II) and
pH 6 for Ag(I), and afterwards reduced at –0.7 V vs. Ag/AgCl in the separate measurement solution (BR buffer pH 5 + 0.05 mol/L
NaNO3) prior to the anodic stripping square-wave voltammetric (ASSWV) detection. For Hg(II) ions, at 15 min accumulation, a linear
range from 1.0 × 10–7 to 8.0 × 10–6 mol/L was obtained, with a 5.7 × 10–8 mol/L limit of detection. The VMCPE response was linear for Ag(I) ions in the concentration range from 2.0 × 10–7 to 8.0 × 10–6 mol/L, at 10 min accumulation with a corresponding limit of detection of 6.3 × 10–8 mol/L. The relative standard deviation of the analytical procedure including accumulation from a 5 × 10–7 mol/L solution of Hg (15 min) or Ag(I) (10 min), electrolysis, ASSWV detection, regeneration and activation of the VMCPE,
was 4% (n = 6). The optimisation of the parameters for the application of the VMCPE in combination with ASSWV detection is presented
and discussed.
Received: 10 July 1997 / Revised: 31 October 1997 / Accepted: 3 November 1997 相似文献
8.
Y. Li Y. Chai R. Yuan W. Liang L. Zhang G. Ye 《Journal of Analytical Chemistry》2008,63(11):1090-1093
A PVC membrane electrode for Al3+ based on glyoxal-bis-thiosemicarbazone (GBTC) as an ion carrier was developed. The electrode exhibits a Nernstian slope of 20.1 mV per decade and a linear range of 1.8
× 10−5−1.0 × 10−1 M for Al(NO3)3 with a detection limit of 8.7 × 10−6 M. It has a fast response time of about 10 s and can be used for at least 1 month. The proposed membrane sensor revealed
a good selectivity for Al3+ over a wide variety of other metal ions and could be used in the pH range of 2.5–4.5.
The text was submitted by the authors in English. 相似文献
9.
Hassan Ali Zamani Mohammad Reza Ganjali Masoud Salavati-Niasari 《Transition Metal Chemistry》2008,33(8):995-1001
A Fe3+ ion-selective membrane sensor was fabricated from polyvinyl chloride (PVC) matrix membrane containing bis-bidentate Schiff
base (BBS) as a neutral carrier, sodium tetraphenyl borate (NaTPB) as anionic excluder, and o-nitrophenyloctyl ether (NPOE) as a plasticizing solvent mediator. The effects of the membrane composition, pH, and additive
anionic influence on the response properties were investigated. The best performance was obtained with a membrane containing
32% PVC, 62.5% NPOE, 3% BBS, and 2.5% NaTPB. The electrode shows a Nernstian behavior (slope of 19.3 ± 0.6) over a very wide
iron ion concentration range (1.0 × 10−7–1.0 × 10−2 M) and has a low detection limit (7.4 × 10−8 M). The potentiometric response of the sensor is independent of pH of the solution in the pH range 1.9–5.1. The proposed
sensor has a very low response time (<15 s) and a good selectivity relative to a wide variety of other metal ions including
common alkali, alkaline earth, heavy, and transition metal ions. The electrode can be used for at least 60 days without any
considerable divergence in potentials. The proposed sensor was successfully applied as an indicator electrode for the potentiometric
titration of 1.0 × 10−2 M Fe3+ ions with a 1.0 × 10−4 M EDTA and the direct determination of Fe3+ in mineral water and wastewater samples. 相似文献
10.
Neetu Bansal 《Transition Metal Chemistry》2010,35(4):483-490
A kinetic method for the determination of organosulfur compounds by UV spectrophotometry is described. Organosulfur compounds
have been shown to inhibit the Hg(II)-catalyzed substitution of cyanide in hexacyanoferrate(II) by 2-methylpyrazine (2-Mepz).
The inhibitory effect is proportional to the concentration of inhibitor and can be used as the basis for the determination
of trace amounts of organosulfur compounds such as cysteine, 2,3-dimercaptopropanol (DMP) and thioglycolic acid (TGA). Both
the influence of the reaction variables and interference of a variety of ions have been studied. A mechanism for the inhibition
process is proposed. The determination range depends on the amount of Hg(II) added and stability of the Hg(II)–ligand complex.
Kinetic parameters were determined from Lineweaver–Burk plots, obtained in the absence and presence of the inhibitor. Excellent
linearity is observed for all analytes over their respective concentration ranges with correlation coefficient >0.9. The condition
calibration curves were linear in the range of 5 × 10−6–15 × 10−6 M for cysteine, 1 × 10−7–7 × 10−7 M for DMP and 1 × 10−6–10 × 10−6 M for TGA. The detection limits were 1.18 × 10−7 M for cysteine, 4.16 × 10−8 M for DMP and 1.30 × 10−7 M for TGA. The effects of amino acids that can interfere in the determination of cysteine were studied. 相似文献
11.
N. Alizadeh S. Ershad H. Naeimi H. Sharghi M. Shamsipur 《Fresenius' Journal of Analytical Chemistry》1999,365(6):511-515
A PVC membrane electrode for copper(II) ions based on a recently synthesized naphthol-derivative Schiff’s base as membrane
carrier was prepared. The sensor exhibits a Nernstian response for Cu2+ ions over a wide concentration range (5.0 × 10–6–5.0 × 10–2 mol/L) with a detection limit of 3.1 × 10–6 mol/L (0.2 μg/mL). It has a very short response time of about 5 s and can be used for ?3 months without any divergence in
potential. The proposed electrode revealed good selectivities over a wide variety of other cations including alkali, alkaline
earth, transition and heavy metal ions and could be used in a pH range of 4.0–7.0. It was successfully applied to the direct
determination and potentiometric titration of copper ion.
Received: 23 February 1999 / Revised: 4 May 1999 / Accepted: 5 May 1999 相似文献
12.
Reza Ansari Ali Fallah Delavar Alireza Aliakbar Ali Mohammad-khah 《Journal of Solid State Electrochemistry》2012,16(3):869-875
A pencil graphite electrode coated by copper (II)–carmoisine dye complex in polyaniline (emeraldine base form) matrix (termed
as PGE/PA/Cu-Car) was prepared and used as copper ion-selective electrode. The introduced electrode was found to have high
selectivity toward copper ion (II) and exhibited wide working concentration range, low response time, and good shelf life.
The sensor electrode showed a linear Nernstian response over the range of 5.0 × 10−6 to 1.0 × 10−1 M with a slope of 29.7 ± 1 mV per decade change in concentration. A detection limit of 2.0 × 10−6 M was obtained. The optimum pH working range of the electrode was found to be 4.0–7.0. 相似文献
13.
Mojtaba Shamsipur Sohrab Ershad Naser Samadi Abloghasem Moghimi Hossein Aghabozorg 《Journal of Solid State Electrochemistry》2005,9(11):788-793
A new modified carbon paste electrode based on a recently synthesized mercury (II) complex of a pyridine containing proton
transfer compound as a suitable carrier for Br− ion is described. The electrode has a linear dynamic range between 3.00×10−2 and 1.0×10−5 M with a near-Nernastian slope of 61.0±0.9 mV per decade and a detection limit of 4.0×10−6 M (0.32 ppm). The potentiometric response is independent of the pH of the solution in the pH range 4.0–8.3. The electrode
possesses the advantages of low resistance, fast response and good over a variety of other anions. It was applied as an indicator
electrode in potentiometric titration of bromide ions and for the recovery of Br− from tap water. 相似文献
14.
A new simple and inexpensive optical chemical sensor for cadmium(II) ions is presented. The cadmium sensing system was prepared
by incorporating 2-amino-cyclopentene-1-dithiocarboxylic acid (ACDA) on a triacetylcellulose membrane. The absorption spectra of the optical sensor membrane in Cd(II) solution showed a maximum
peak at 430 nm. The proportionality in intensity of the membrane color on the optode to varying amounts of Cd(II) suggests
its potential applications for screening Cd(II) in aqueous samples by visual colorimetry. The sensor provided a wide concentration
range of 3.0 × 10−6–3.4 × 10−4 M of Cd(II) ions with a detection limit of 1.0 × 10−6 M (0.2 μg/mL). The relative standard deviations for eight replicate measurements of 8.0 × 10−6 and 5.0 × 10−5 M Cd(II) were 2.7 and 2.3%, respectively. The response time of the optode was 6 min. The influence of interfering ions on
the determination of 1.0 × 10−5 M Cd(II) was studied and the main interferences were removed by extraction method. The sensor was applied to the determination
of Cd(II) in water samples. 相似文献
15.
《Monatshefte für Chemie / Chemical Monthly》2010,385(1):829-839
Abstract
The construction, performance, and application of a new PVC membrane electrode for determination of the mercury(II) ion, based on 8,17-bis(pyren-1-ylmethyl)-6,7,8,9,15,16,17,18-octahydrodibenzo[f,m][1,8,4,11]dithiadiazacyclotetradecine as an ionophore, is described. The effects of factors such as membrane composition, the nature and amount of the plasticizers and additives, and pH for the improved sensitivity of the electrode were studied. The electrode had a Nernstian response for mercury(II) ions over the concentration range 1.0 × 10−2–1.0 × 10−6 mol dm−3 with a slope of 27.6 ± 0.6 mV/pHg. The detection limit for mercury(II) was 7.9 × 10−7 mol dm−3. The response time of the electrode was between 5 and 15 s, depending on the concentration of mercury, and it can be used in a pH range 4.0–4.5 for approximately 4 months without any substantial divergence of the response characteristics. It showed higher selectivity for mercury(II) ions than for several common alkali, alkaline earth, and transition metal ions except silver(I). The proposed electrode was successfully applied to direct determination of mercury in a dental filling amalgam alloy as a real sample with a complex matrix and as an indicator electrode in complexation titrations. 相似文献16.
Maha El-Tohamy Sawsan Razeq Magda El-Maamly Abdalla Shalaby 《Central European Journal of Chemistry》2010,8(4):937-945
The construction and performance characteristics of phenytoin sodium selective electrodes are detailed. Two types of electrodes:
plastic membrane I and coated wire II, were constructed based on the incorporation of phenytoin sodium with tungstosilicic
acid. The influence of membrane composition, kind of plasticizer, pH of the test solution, soaking time and the electrodes’
foreign ions were investigated. The electrodes showed a Nernstian response with a mean calibration graph slope of 30.9±0.1
and 28.9±0.1 mV decade−1 at 25°C for electrode I and II respectively, over a phenytoin sodium concentration range of 5×10−3−5×10−6 M and 1×10−3−1×10−6 M with a detection limit 1.3×10−6 M and 2.5×10−7 M for electrode I and II, respectively. The electrodes gave average selective precision and were usable within the pH range
6–10. Interference studies from common cations, alkaloids, sugars, amino acids and drug excipients are reported. The results
obtained by the proposed electrodes were also applied successfully for the determination of the drug in pharmaceutical preparations
and biological fluids. 相似文献
17.
Krishnapillai Girish Kumar Remalakshmy Poduval Sareena John Pearl Augustine 《Mikrochimica acta》2006,156(3-4):283-287
A new PVC membrane sensor, which is highly selective towards Ni (II) ions, has been developed using a thiophene-derivative
Schiff base as the ionophore. The best performance was exhibited by the membrane having the composition percentage ratio of
5:3:61:31 (ionophore:NaTPB:DBP:PVC) (w/w), where NaTPB is the anion excluder, sodium tetraphenylborate and DBP is the plasticizing
agent (dibutyl phthalate). The membrane exhibited a good Nernstian response for nickel ions over the concentration range of
1.0 × 10−1–5.0 × 10−6 M (limit of detection is 1.8 × 10−6 M) with a slope of 29.5 ± 1.0 mV per decade of activity. It has a fast response time of <20 s and can be used for a period
of 4 months with good reproducibility. The sensor is suitable for use in aqueous solutions of a wide pH range of 3.2–7.9.
The sensor shows high selectivity to nickel ions over a large number of mono-, bi- and trivalent cations. It has been successfully
used as an indicator electrode in the potentiometric titration of nickel ions against EDTA and also for direct determination
of nickel content in real samples – wastewater samples from electroplating industries and Indian chocolates. 相似文献
18.
T. V. Maltseva E. O. Kudelko V. N. Belyakov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(13):2336-2339
It was studied the equilibrium adsorption and adsorption kinetics of Cu(II), Cd(II), Pb(II), and Cr(VI) by composite hydroxides
formed by Me
x
O
y
· nH2O and Me0.4–0.7Al0.6–0.3O
y
· nH2O, where Me = Zr, Sn and Ti. It was estimated the values of the diffusion coefficients of adsorbed ions Cu(II) and Cr(VI)
from kinetic values. It was established that the estimated diffusion coefficients of adsorbed ions Cu(II) are in the range
0.4 × 10−12–2.5 × 10−12 m2/s for individual hydroxides and 1.2 × 10−12–2.8 × 10−12 m2/s for double hydroxides. The obtained values of diffusion coefficients Cr (VI) for double hydroxides are 0.1 × 10−10–0.4 × 10−10 m2/s. 相似文献
19.
Ahmad Soleymanpour Bahram Garaili S. Masoud Nabavizadeh 《Monatshefte für Chemie / Chemical Monthly》2008,139(12):1439-1445
Three platinum(II) complexes were synthesized and studied to characterize their ability as an anion carrier in a PVC membrane electrode. The polymeric membrane electrodes (PME) and also coated glassy carbon electrodes (CGCE) prepared with
one of these complexes showed excellent response characteristics to perchlorate ions. The electrodes exhibited Nernstian responses to ClO4
− ions over a wide concentration range from 1.5 × 10−6 to 2.7 × 10−1 M for PME and 5.0 × 10−7 to 1.9 × 10−1 M for CGCE with low detection limits (9.0 × 10−7 M for PME and 4.0 × 10−7 M for CGCE). The electrodes possess fast response time, satisfactory reproducibility, appropriate lifetime and, most importantly,
good selectivity toward ClO4
− relative to a variety of other common anions. The potentiometric response of the electrodes is independent of the pH of the test solution in the pH range 2.0–9.0. The proposed sensors were used in potentiometric determination of perchlorate ions in mineral water and urine
samples.
Correspondence: Ahmad Soleymanpour, Department of Chemistry, Damghan Basic Science University, Damghan, Iran. 相似文献
20.
Electrochemical detection of copper(II) at a gold electrode modified with a self-assembled monolayer of penicillamine 总被引:1,自引:0,他引:1
A penicillamine (PCA) self-assembled monolayer (SAM) was prepared on a gold electrode. It has been found that the modified
electrode exhibited a selective response to copper ions. As demonstrated by cyclic voltammetric experiments, the SAM-based
electrode showed an attractive ability to preconcentrate efficiently traces of copper(II) from solutions. Under optimum conditions,
the anodic peak current was proportional to the concentration of Cu(II) in the range from 8.0 × 10−7 to 1.0 × 10−4 M with a detection limit of 4.0 × 10−7 M. Moreover, this modified gold electrode is also characterized by excellent repeatability, showing a relative standard deviation
of 3.2% for nine successive measurements of 1.0 × 10−5 M Cu(II). The PCA/Au SAM gold electrode was used for the determination of Cu(II) in a tap water sample and the results showed
a good agreement with the data obtained by atomic emission spectrometry.
The text was submitted by the authors in English. 相似文献