共查询到20条相似文献,搜索用时 546 毫秒
1.
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
2.
A polystyrene-based membrane of 7,8:16,17-dibenzo-6,9,15,18-tetraoxo-1,5,10,14-tetrathiacyclooctadeca-7,16-diene [Bz2Oxo4(18)dieneS4] was fabricated using sodium tetraphenylborate (NaTPB) and dioctyl phthalate (DOP) as anion excluder and plasticizing agent.
The best performance was obtained from the membrane with the composition ionophore [Bz2Oxo4(18)dieneS4]:polystyrene:DOP:NaTPB, 5:100:150:10 (w/w). The response of the electrode was linear over a wide range of concentration, 1.26×10–6–1.00×10–1 mol L−1 for silver ion with a Nernstian slope of 58.4±0.1 mV per decade and a detection limit of 1.0×10−6 mol L−1. The electrode was found to be chemically inert and of adequate stability with a response time of 10 s and could be used
for a period of 3 months without change of potential. It worked satisfactorily in mixtures containing up to 35% (v/v) non-aqueous content. The proposed membrane sensor had good selectivity for Ag+ over a wide variety of metal ions in the pH range 2.2–8.5. It was successfully used as an indicator electrode in potentiometric
titration of silver ion. The electrode was also useful for determination of Ag+ in waste from photographic films. 相似文献
3.
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
4.
A.K. Singh Puja Saxena Amit Panwar 《Journal of inclusion phenomena and macrocyclic chemistry》2006,54(3-4):299-305
Copper (II) complex of 2,4-dimethyl-1,5,9,12-tetraazacyclopentadeca-1,4-diene, [Me2(15)dieneN4] was synthesized and used in the fabrication of Cu2+ – selective ISE membrane in PVC matrix. The membrane having Cu(II) macrocyclic complex as electroactive material along with sodium tetraphenyl borate (NaTPB) as anion discriminator. Dibutyl phthalate (DBP) as plasticizer in poly(vinyl chloride) (PVC) matrix was prepared for the determination of Cu2+. The best performance was observed by the membrane having Cu(II) complex–PVC–NaTPB–DBP with composition 1:5:1:3. The sensor worked well over a concentration range 1.12 × 10−6 M–1.0 × 10−1 M between pH 2.1–6.2 and a fast response time 10±2 s and a lifetime of 6 months. Their performance in partially non-aqueous medium was found satisfactory. Electrodes exhibited excellent selectivity for Cu2+ ion over other mono-, di-, trivalent cations. It can also be used as indicator electrode in the potentiometric titration of Cu2+ against EDTA as well as in the determination of Cu2+ in real samples. 相似文献
5.
A PVC membrane electrode for zinc ions based on cryptand C2B22 as membrane carrier was prepared. The electrode exhibits a linear stable response over a wide concentration range (5.0
× 10–2– 5.0 × 10–5 mol/L) with a slope of 24 mV/ decade and a limit of detection of 3.98 × 10–5 mol/L (2.6 μg/g). It has a fast response time of about 30 s and can be used for at least 4 months without any divergence
in potential. The proposed sensor revealed good selectivities for Zn2+ over a wide variety of other metal ions and could be used in a pH range of 4–7. It was used as an indicator electrode in
potentiometric titration of zinc ion.
Received: 26 February 1998 / Revised: 25 May 1998 / Accepted: 28 May 1998 相似文献
6.
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
7.
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
8.
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
9.
Heterocyclic thiocarboxylic acids have been designed to prepare polymeric membrane ion-selective electrode (ISE) for Pb2+. Construction, response characteristic and application of the lead ISEs are investigated. Better results have been obtained
with membranes containing ligands L1∼L3 with bis(2-ethylhexyl) sebacate (DOS) as a plasticizer. Ionophores L1∼L3 are [(4,6-dimethyl-2-pyrimidinyl) thio] acetic acid (L1), (1,3,4-thiadiazole-2,5-diyldithio) diacetic acid (L2) and (1,3,4-thiadiazole-2,5-diyldithio) dipropionic acid (L3). The optimum electrodes have the composition of L1 (1.6): PVC (32.7): DOS (65.3): KT
p
ClPB (0.4) (w/w), L2 (1.0): PVC (32.8): DOS (66.0): KT
p
ClPB (0.2) (w/w), and L3 (1.0): PVC (32.7): DOS (65.4): KT
p
ClPB (0.9) (w/w). The optimized membrane electrodes work well over a wide range of concentrations (1.0 × 10−5 ∼1.0 × 10−2 M, 1.0 × 10−6 ∼1.0 × 10−2 M, and 1.0 × 10−6 ∼1.0 × 10−2 M) with the response slope of 27.4, 30.1 and 29.2 mV/decade, respectively. Potentiometric selectivities of the ISEs based
on L1 ∼ L3 for Pb2+ over other interfering ions are determined with the fix interference method. The electrodes display good selectivity over
a number of alkali, alkaline earth, transition and heavy metal ions. The lifetime of the electrodes is about 2 months and
their response time is 20 s. Applications of these electrodes for the determination of lead in real samples and as indicator
electrodes for potentiometric titration of Na2SO4 using Pb2+ solution are reported. 相似文献
10.
Ashok Kumar Singh Ravindra Pratap Singh Sameena Mehtab 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(1-2):9-15
A new polystyrene based membrane electrode of methyl substituted 6,7:13,14-dibenzo-2,4,9,11-tetraphenyl-1,5,8,12-tetraazacyclotetradeca-1,4,6,8,11,13-hexaene
(I) with sodium tetraphenylborate (NaTPB) and dibutyl phthalate (DBP) as anion excluder and plasticizing agent was prepared and
investigated as Hg (II)-selective electrode. The electrode exhibits a Nernstian response for Hg (II) ions over a wide concentration
range of 1.0 × 10−1–8.9 × 10−6 M with a slope of 30 ± 1 mV per decade concentration. It has a response time of 10 s and can be used for at least 4 months
without any divergence in potentials. The membrane works satisfactorily in a partially non-aqueous medium up to a maximum
30% (v/v) content of methanol and ethanol. The proposed sensor revealed good selectivity over a wide variety of other cations
including alkali, alkaline earth, heavy and transition metal ions and could be used in a pH range of 2.5–5.0. Normal interferents
like Ag+, Cd2+ and Pb2+ low interfere in the working of the electrode. The electrode was successfully used in the direct determination of Hg2+ in aqueous solution. 相似文献
11.
Tripodal chelating ligand-based sensor for selective determination of Zn(II) in biological and environmental samples 总被引:1,自引:0,他引:1
Potassium hydrotris(N-tert-butyl-2-thioimidazolyl)borate [KTtt-Bu] and potassium hydrotris(3-tert-butyl-5-isopropyl-l-pyrazolyl)borate [KTpt-Bu,i-Pr] have been synthesized and evaluated as ionophores for preparation of a poly(vinyl chloride) (PVC) membrane sensor for Zn(II)
ions. The effect of different plasticizers, viz. benzyl acetate (BA), dioctyl phthalate (DOP), dibutyl phthalate (DBP), tributyl
phosphate (TBP), and o-nitrophenyl octyl ether (o-NPOE), and the anion excluders sodium tetraphenylborate (NaTPB), potassium tetrakis(p-chlorophenyl)borate (KTpClPB), and oleic acid (OA) were studied to improve the performance of the membrane sensor. The best
performance was obtained from a sensor with a of [KTtt-Bu] membrane of composition (mg): [KTtt-Bu] (15), PVC (150), DBP (275), and NaTPB (4). This sensor had a Nernstian response (slope, 29.4 ± 0.2 mV decade of activity)
for Zn2+ ions over a wide concentration range (1.4 × 10−7 to 1.0 × 10−1 mol L−1) with a limit of detection of 9.5 × 10−8 mol L−1. It had a relatively fast response time (12 s) and could be used for 3 months without substantial change of the potential.
The membrane sensor had very good selectivity for Zn2+ ions over a wide variety of other cations and could be used in a working pH range of 3.5–7.8. The sensor was also found to
work satisfactorily in partially non-aqueous media and could be successfully used for estimation of zinc at trace levels in
biological and environmental samples.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
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
13.
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
14.
Joanna Wiśniewska 《Transition Metal Chemistry》2007,32(6):811-815
The kinetics of the electron-transfer reactions between promazine (ptz) and [Co(en)2(H2O)2]3+ in CF3SO3H solution ([CoIII] = (2–6) × 10−3
m, [ptz] = 2.5 × 10−4
m, [H+] = 0.02 − 0.05 m, I = 0.1 m (H+, K+, CF3SO
3
−
), T = 288–308 K) and [Co(edta)]− in aqueous HCl ([CoIII] = (1 − 4) × 10−3
m, [ptz] = 1 × 10−4
m, [H+] = 0.1 − 0.5 m, I = 1.0 m (H+, Na+, Cl−), T = 313 − 333 K) were studied under the condition of excess CoIII using u.v.–vis. spectroscopy. The reactions produce a CoII species and a stable cationic radical. A linear dependence of the pseudo-first-order rate constant (k
obs) on [CoIII] with a non-zero intercept was established for both redox processes. The rate of reaction with the [Co(en)2(H2O)2]3+ ion was found to be independent of [H+]. In the case of the [Co(edta)]− ion, the k
obs dependence on [H+] was linear and the increasing [H+] accelerates the rate of the outer-sphere electron-transfer reaction. The activation parameters were calculated as follows:
ΔH
≠ = 105 ± 4 kJ mol−1, ΔS
≠ = 93 ± 11 J K−1mol−1 for [Co(en)2(H2O)2]3+; ΔH
≠ = 67 ± 9 kJ mol−1, ΔS
≠ = − 54 ± 28 J K−1mol−1 for [Co(edta)]−. 相似文献
15.
Jonathan F. Ojo Jide Ige Grace O. Ogunlusi Olanrewaju Owoyomi Esan S. Olaseni 《Transition Metal Chemistry》2006,31(3):337-339
The reactions between Fe(Phen)32+[phen = tris-(1,10) phenanthroline] and Co(CN)5X3− (X = Cl, Br or I) have been studied in aqueous acidic solutions at 25 °C and ionic strength in the range I = 0.001–0.02 mol dm−3 (NaCl/HCl). Plots of k2 versus √I, applying Debye–Huckel Theory, gave the values −1.79 ± 0.18, −1.65 ± 0.18 and 1.81 ± 0.10 as the product of charges (ZAZB) for the reactions of Fe(Phen)32+ with the chloro-, bromo- and iodo- complexes respectively. ZAZB of ≈ −2 suggests that the charge on these CoIII complexes cannot be −3 but is −1. This suggests the possibility of protonation of these CoIII complexes. Protonation was investigated over the range [H+] = 0.0001 −0.06 mol dm−3 and the protonation constants Ka obtained are 1.22 × 103, 7.31 × 103 and 9.90 × 102 dm6 mol−3 for X = Cl, Br and I, respectively. 相似文献
16.
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
17.
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
18.
A new highly selective terbium(III) electrode was prepared with a polymeric film doped using S-2-benzothiazolyl-2-amino-α-(methoxyimino)-4-thiazolethiol acetate as an electroactive material, benzyl acetate (BA) as a plasticizer, and potassium
tetrakis(4-chlorophenyl) borate (KTpClPB) as an anionic site in the percentage ratio 3.17:1.58:63.4:31.7 (ionophore-KTpClPB-BA-PVC,
w/w). The electrode exhibited a linear response with a near Nernstian slope of 19.5 mV/decade within the concentration range
1.5 × 10−7−1.0 × 10−2 M terbium ions, with a working pH range from 2.0 to 8.0, and a fast response time of 10 s and presented satisfactory reproducibility.
The limit of detection was 9.3 × 10−8 M. The results show that this electrode can be used in ethanol media up to 30% (v/v) concentration without interference.
It can be used for 3 months without any considerable divergence in the potentials. Selectivity coefficients for terbium(III)
with respect to many cations were investigated. The electrode is highly selective for terbium(III) ions over a large number
of monovalent, bivalent, and trivalent cations. This shows the valuable property of the proposed electrode. The stability
constant of the ionophore towards Tb3+ ions was determined with the sandwich membrane method. It was successfully used as an indicator electrode in potentiometric
determination of terbium(III) ions with EDTA and in direct determination in tap water and binary mixtures with quantitative
results. The utility of the proposed electrode was also determined in the presence of ionic and nonionic surfactants and in
the presence of fluoride ions in four pharmaceutical (mouthwash) preparations.
Figure Structure of S-2-Benzothiazolyl-2-amino-α-(methoxyimino)-4-thiazolethiol acetate 相似文献
19.
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
20.
Highly selective poly(vinyl chloride) (PVC) membrane electrode based on N-salicylidene-benzylamineato copper(II) complexes
[Cu(SBA)2] as new carriers towards thiocyanate-selective electrode was reported. The influence of membrane composition, pH and possible
interfering anions were investigated on the response properties of the electrode. The resulting electrode exhibits anti-Hofmeister
selectivity sequence: SCN− > ClO4− > Sal− > I− > Br− > NO3− > NO2− > SO32− > H2PO4− > Cl− > SO42−, and a near-Nernstian potential linear range for thiocyanate from 1.0 × 10−1 to 9.0 × 10−7 M with a detection limit of 7.0 10−7 M and a slope of , over a wide pH range of 3.0–9.0 in phosphate buffer solution at 20°C. The proposed electrode has a fast response time of
about 5–10 s and can be used for at least 3 months without any considerable divergence in potential. The electrode was successfully
applied to the determination of thiocyanate in waste water and human urine and saliva samples.
Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 3, pp. 293–299.
The text was submitted by the authors in English. 相似文献