共查询到20条相似文献,搜索用时 15 毫秒
1.
Mahsa Majidian Jahan Bakhsh Raoof Sayed Reza Hosseini Reza Ojani 《Journal of the Iranian Chemical Society》2017,14(6):1263-1270
In this work, an antimony trioxide-modified multi-walled carbon nanotube paste electrode (Sb2O3/CNTPE) was employed for determination of Cu2+ ions by using square wave anodic stripping voltammetry (SWASV) in the presence of 8-hydroxy-7-iodo-5-quinoline sulfonic acid (HIQSA) as a chelating agent. The field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS) methods were applied to estimate the morphology and properties of the modified electrode. Measurements related to SWASV were taken in 0.6 M HCl at ?1.0 V versus Ag|AgCl|KCl (3 M) for 90 s (deposition step). After equilibrium time of 15 s, an ASV appeared at 0.0 V versus Ag|AgCl|KCl (3 M) (stripping step). The sensor depicted a fairly linear response for Cu2+ in the concentration range of 2–100 ppb with appropriate detection limit about 0.39 ppb and limit of quantification about 1.3 ppb. The stability of the modified electrode during 7 weeks and its behavior in the presence of some metal ions was evaluated. The practical applicability of the Sb2O3/CNTPE was established on the voltammetric determination of Cu2+ in tap water as a sample. 相似文献
2.
Yao Fei Zhang-Ying Lv Ai-Jun Wang Ye-Hong Chen Jian-Rong Chen Jiu-Ju Feng 《Mikrochimica acta》2014,181(3-4):389-394
A glassy carbon electrode was modified with gold hierarchical dendrites (Au HDs) by one-step electrodeposition in the presence of cytosine, which plays an important role in the formation of the Au HDs. This approach is simple, fast, feasible, controllable, without any seed, template, or surfactant. The modified electrodes were used for the simultaneous determination of Pb2+ and Cu2+ by square wave stripping voltammetry. The peak currents show good linear relationship with concentrations of Pb2+ and Cu2+ in the range of 5.0 to 15.0 μM. The recoveries of the spiked water samples are in the range of 94.0 %–107.4 % for Pb2+ and Cu2+, and their relative standard deviation are in the range of 2.7 %–4.3 % for Pb2+ and Cu2+, respectively (n?=?3). Figure
Well-defined Au hierarchical dendrites (HDs) modified electrodes were prepared by a simple, fast, feasible and controllable electrochemical route. The modified electrode was developed for the simultaneous and sensitive detection of Pb2+ and Cu2+ by square wave stripping voltammetry. 相似文献
3.
Determination of trace metoclopramide by anodic stripping voltammetry with nafion modified glassy carbon electrode 总被引:4,自引:0,他引:4
A novel method is described for determination of metoclopramide (MCP) by second-derivative adsorptive anodic stripping voltammetry with a nafion-modified electrode. The stripping peak current is proportional to the concentration of MCP over the range 1.2×10−9–4.6×10−7 M. The detection limit is 8.0×10−11 M with 4-min accumulation. The method has been successfully applied to the determination of MCP in human serum. 相似文献
4.
Gongjun Yang Xilong Qu Ming Shen Chengyin Wang Qishu Qu Xiaoya Hu 《Mikrochimica acta》2008,160(1-2):275-281
Poly(phenol red) (denoted as PPR) films were electrochemically synthesized on the surface of a glassy carbon electrode (GCE)
by cyclic voltammetry to obtain a chemically modified electrode (denoted as PPR-GCE). The growth mechanism of PPR films was
studied by attenuated total reflection spectroscopy. This PPR-GCE was used to develop a novel and reliable method for the
determination of trace Pb2+ by anodic stripping differential pulse voltammetry. At optimum conditions, the anodic peak exhibits a good linear concentration
dependence in the range from 5.0 × 10−9 to 5.0 × 10−7 mol L−1 (r = 0.9989). The detection limit is 2.0 × 10−9 mol L−1 (S/N = 3). The method was employed to determine trace levels of Pb2+ in industrial waste water samples.
Correspondence: Gongjun Yang, Ming Shen, College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002,
P.R. China 相似文献
5.
Xiuhui He Li Chen Xuan Xie Zhaohong Su Cong Qin Ying Liu Ming Ma Shouzhuo Yao Le Deng Qingji Xie Yun Tian Dilan Qin Yueping Luo 《Mikrochimica acta》2012,176(1-2):81-89
We report on a glassy carbon electrode (GCE) modified with a lead ionophore and multiwalled carbon nanotubes. It can be applied to square wave anodic stripping voltammetric determination of Pb(II) ion after preconcentration of Pb(II) at ?1.0?V (vs. SCE) for 300?s in pH?4.5 acetate buffer containing 400?μg?L?1 of Bi(III). The ionophore-MWCNTs film on the GCE possesses strong and highly selective affinity for Pb(II) as confirmed by quartz crystal microbalance experiments. Under the optimum conditions, a linear response was observed for Pb(II) ion in the range from 0.3 to 50?μg?L?1. The limit of detection (at S/N?=?3) is 0.1?μg?L?1. The method was applied to the determination of Pb(II) in water samples with acceptable recovery. Figure
A glassy carbon electrode modified with a lead ionophore and multiwalled carbon nanotubes is successfully applied to sensitive and selective square wave anodic stripping voltammetric determination of Pb(II) ion after preconcentration of Pb(II) at ?1.0?V (vs. SCE) in pH?4.5 solutions containing 400?μg?L?1 of Bi(III). 相似文献
6.
Optimum conditions for the use of the bare glassy carbon electrode (GCE) are reported. Linear calibration graphs are obtained in the range 5 × 10-7–3.5 × 10-5 M copper(II). The detection limit for copper(II) is 5.9 × 10-9 M at pH 4.5 and 3.3 × 10-8 M at pH 6.5. 相似文献
7.
Yusong Li Guangqiang Sun Yuehua Zhang Cunwang Ge Ning Bao Yihong Wang 《Mikrochimica acta》2014,181(7-8):751-757
Single-walled bismuth nanotubes (sw-BiNTs) were self-assembled with octa(3-aminopropyl) silsesquioxane as a framework and to govern morphology. Deposited on a glassy carbon electrode (GCE), the sw-BiNTs were used for the simultaneous analysis of Pb(II) and Cd(II) by square wave stripping voltammetry. The sw-BiNTs were prepared by (a) coordination interaction between the amino groups of the silsesquioxane and the Bi(III) ions, and by (b) reduction with sodium borohydride. Transmission electron microscopy images revealed single-walled tubular structures with diameters of ~4–6 nm, and with lengths of several hundreds nanometers. GCEs modified with such sw-BiNTs perform much better than bare GCEs in stripping analysis of Pb(II) and Cd(II). The effects of adsorption quantity of sw-BiNTs, solution pH, pulse amplitude, and pulse width were optimized. The modified electrode was then used for the analysis of Pb(II) and Cd(II) in a linear response range from 0.4 to 6 μM with a sensitivity of 4.692 μA μM?1 and 3.835 μA μM?1, and detection limits of 1 nM and 5 nM, respectively. The method was successfully applied to the analysis of Pb(II) and Cd(II) in toy leachates, and the results were in good agreement with those obtained with atomic absorption spectrometry. Sensitivity and detection limits were compared with other voltammetric methods, and the sw-BiNTs are deemed to be an attractive alternative for practical applications. Other features of the electrode include low costs, a well reproducible nanostructure, and ease of scale-up of the fabrication process. Figure
Single-walled bismuth nanotubes (BiNTs) were self-assemblied with octa(3-aminopropyl) silsesquioxane as framework and morphology control agent for the simultaneous detection of trace Pb(II) and Cd(II) by square wave stripping voltammetry. The proposal preparation avoids time-consuming pre-treatment and experienced operation. The sensitivity and detection limit of the method was comparable to reported voltammetric methods, and BiNTs might be an alternative candidate for practical applications of electrochemical detection. 相似文献
8.
Copper at the low or fractional ng g?1 level in 0.1 M oxalic acid solutions at pH 1.6 is electrodeposited on a chemically-modified glassy carbon electrode with surface-bound groups at ?0.6 V vs. Ag/AgCl (3.3 M KCl). The deposit is then anodically stripped in the same solution, a current-potential curve being recorded by the differential-pulse technique. The advantages of this electrode over an unmodified glassy carbon electrode include higher sensitivity, precision and selectivity; the modified electrode can be used 50–100 times without further treatment. 相似文献
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11.
Binding constants of lead by humic and fulvic acids studied by anodic stripping square wave voltammetry 总被引:1,自引:0,他引:1
A better understanding of metal ion binding to soil organic substances is of fundamental importance in geochemical modeling
of environments. Fulvic acids (FA) and humic acids (HA) make up an important part of soil organic matter, and their binding
capacity affects the fate of metal ions and plays an important role in their mobility. Binding constants of Pb(II) to HA and
FA were evaluated by anodic stripping square wave voltammetry (ASSWV) where the binding reaction was performed at pH 4.5 in
a medium of 0.020 mol l−1 KNO3. Results showed that ASSWV technique was well suited for the estimation of the binding capacity of a natural organic matter
towards heavy metals. Based on the voltammetric titration curves, binding constants of Pb(II) complexes formed with HA and
FA were 0.78 × 106 and 0.15 × 106 mol−1 l, which indicated that complex of Pb2+ with HA was more stable than with FA. The average molecular weight of HA and FA prepared from soil samples were also found
to be 1821 g mol−1 and 805 g mol−1, respectively. 相似文献
12.
The application of an in situ gold-plated glassy carbon disk electrode to the determination of selenium(IV) by anodic stripping voltammetry is described. A single anodic stripping peak is obtained for solutions containing less than 1 × 10-6 M Se(IV). The minimum concentration detected was 2 × 10-9 M Se(IV). The determination of selenium in NBS SRM 1577 (Bovine Liver) by anodic stripping voltammetry with an in situ goldplated rotating glassy carbon electrode yielded a value of 1.14 ± 0.07 μg Se g-1 compared with a certificate value of 1.1 ± 0.1 μg Se g-1. 相似文献
13.
Phenylephrine (i.e. PHE) and chlorprothixene (i.e. CPT), two effective and important antipsychotic drugs with low redox activity, were found generating an irreversible anodic peak at about +0.89 V (vs. SCE) and +1.04 V in 0.05 M HAc–NaAc (pH 5.0) or NH2CH2COOH–HCl (pH 2.4) buffer solution at poly(4-aminobenzene sulfonic acid) modified glassy carbon electrode (i.e. poly(4-ABSA)/GC), respectively. Sensitive and quantitative measurement for them based on the anodic peaks was established under the optimum conditions. The anodic peak current was linear to PHE and CPT concentrations from 1 × 10−7 to 1.5 × 10−5 M and 2 × 10−6 to 4.5 × 10−5 M, the detection limits obtained were 1 × 10−8 and 1 × 10−7 M, separately. The modified electrode exhibited some excellent characteristics including easy regeneration, high stability, good reproducibility and selectivity. The method proposed was successfully applied to the determination of PHE and CPT in drug injections or tablets and proved to be reliable compared with ultraviolet spectrophotometry. The modified electrode was characterized by electrochemical methods. 相似文献
14.
In the present work, carbon paste electrodes (CPE) modified with conducting polymers 1,8-diaminonaphtalene (DAN) was developed for the voltammetric determination of Cu(II). The modified electrode exhibited a significantly increased sensitivity
and selectivity for Cu2+ compared with a bare carbon paste electrode. Copper(II) was preconcentrated at open circuit on the modified electrode. The
measurements were carried out using a rotating disk electrode (RDE) as working electrode. The experimental parameters for the determination of Cu(II) were optimized. The Cu(II) ions were chemically
deposited onto the surface of poly DAN-CPE in an acidic medium. Under the optimum conditions, a linear calibration graph was
obtained in the concentration range of 0.1 to 250 ppb with a correlation coefficient of 0.9998. The relative standard deviation
for 6 successive determinations was 4.7%. A study of interfering substances was also performed, and the method was applied
to the direct determination of copper in real samples like tap water and orange juice samples.
The article is published in the original. 相似文献
15.
This study presents a method for the selective determination of Hg(II) using electromembrane extraction (EME), followed by square wave anodic stripping voltammetry (SWASV), using a gold nanoparticle-modified glassy carbon electrode, (AuNP/GCE). By applying an electrical potential of typically 60 V for 12 min through a thin supported liquid membrane (1-octanol), Hg(II) ions are extracted from a donor phase (i.e., the sample solution) to an acidic acceptor solution (15 μL) placed in the lumen of a hollow fiber. The influences of experimental parameters during EME were optimized using face-centered central composite design. The calibration plot, established at a working voltage of 0.55 V (vs. Ag/AgCl), extends from 0.2 to 10 μg.L?1 of Hg(II). The limit of detection, at a signal to noise ratio of 3, is 0.01 μg.L?1 and the relative standard deviations (for 5 replicate determinations at 3 concentration levels) are between 7.5 and 8.7 %. The method was successfully applied to the determination of Hg(II) in spiked real water samples to give recoveries ranging from 89 to 97 %. The results were validated by cold vapor atomic absorption spectroscopy. 相似文献
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17.
Raewyn M. Town 《Electroanalysis》1997,9(5):407-415
The utility of potentiometric stripping analysis (PSA) for studying the interaction of fulvic acid with CuII and PbII at pH 1.8 and 4.8 was assessed. The impact of fulvic acid on both the deposition and stripping steps was considered. In contrast to results obtained by anodic stripping voltammetry, fulvic acid influenced both these steps in PSA, and to different degrees. Surface active substances have been claimed to have self-compensatory effects in PSA; this work shows that this is not valid for heterogenous natural complexants such as fulvic acid. 相似文献
18.
A simple and effective chemically modified carbon paste electrode (CMCPE) for the simultaneous determination of lead(II) and cadmium(II) was developed in this work. The electrode was prepared by the addition of diacetyldioxime into a carbon paste mixture. Pb2+ and Cd2+ were preconcentrated on the surface of the modified electrode by complexing with diacetyldioxime and reduced at a negative potential (−1.10 V). Then the reduced products were oxidized by differential pulse stripping. The fact that two stripping peaks appeared on the voltammograms at the potentials of −0.65 V (Cd2+) and −0.91 V (Pb2+) demonstrates the possibility of simultaneous determination of Pb2+ and Cd2+. Under the optimized working conditions, calibration graphs were linear in the concentration ranges of 1.0×10−7-1.5×10−5 mol l−1 (Pb2+) and 2.5×10−7-2.5×10−5 mol l−1 (Cd2+), respectively. For 5 min preconcentration, detection limits of 1×10−8 mol l−1 (Pb2+) and 4×10−8 mol l−1 (Cd2+) were obtained at the signal noise ratio (SNR) of 3. To evaluate the reproducibility of the newly developed electrode, the measurements of 5×10−7 mol l−1 Pb2+ and Cd2+ were parallel carried out for six times at different electrodes and the relative standard deviations were 2.9% (Pb2+) and 3.2% (Cd2+), respectively. Interferences by some metals were investigated. Only Ni2+ and Hg2+ apparently affected the peak currents of Pb2+ and Cd2+. The diacetyldioxime modified carbon paste electrode was applied to the determination of Pb2+ and Cd2+ in water samples. The results indicate that this electrode is sensitive and effective for the simultaneous determination of Pb2+ and Cd2+. 相似文献
19.
Roa G Ramírez-Silva MT Romero-Romo MA Galicia L 《Analytical and bioanalytical chemistry》2003,377(4):763-769
This work reports the use of and -cyclodextrin-modified carbon paste electrodes (CPE-CD and CPE-CD) to determine simultaneously Pb(II) and Cd(II) by means of the electrochemical technique known as anodic stripping voltammetry (ASV). Both modified electrodes displayed good resolution of the oxidation peaks of the said metals. Statistic analysis of the results strongly suggests that the CPE-CD exhibited a better analytical response that the CPE-CD, while the detection limits obtained for Pb(II) were 6.3×10–7 M for the CPE-CD and 7.14×10–7 M for the CPE-CD, whereas for Cd(II) they were 2.51×10–6 M for the CPE-CD and 2.03×10–6 M for the CPE-CD. 相似文献
20.
利用循环伏安法制备了聚对氨基苯磺酸修饰电极, 研究了尿酸在该修饰电极上的电化学行为. 结果表明, 该电极对尿酸有较强的电催化作用, 并对抗坏血酸有较强的抗干扰能力. 在pH 5.6的乙酸盐缓冲溶液中, 用循环伏安法和差分脉冲伏安法在该电极上测定了尿酸, 其线性范围分别为1.0×10-5~2.0×10-4 mol/L和4.0×10-7~1.0×10-5 mol/L, 检出限分别为6.0×10-6 mol/L和1.0×10-7 mol/L. 已用于尿液中尿酸的测定. 相似文献