共查询到19条相似文献,搜索用时 140 毫秒
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铋膜玻碳电极阳极溶出伏安法测定异烟肼的研究 总被引:3,自引:0,他引:3
研究了异烟肼在铋膜玻碳电极上的电化学行为检测方法。在0.1mol/L pH=4.5的HAc—NaAc缓冲溶液的底液中,通过富集,用铋膜玻碳电极进行阳极溶出伏安法测定异烟肼。异烟肼的阳极峰电位为-1.02V(vs.SCE),峰电流与异烟肼的浓度在1.6×10~(-7)~8.0×10~(-5)mol/L范围内呈良好的线性关系。该方法的检出下限为8.0×10~(-8)mol/L。对异烟肼含量用本法进行了测定,获得了满意的结果。本方法的优点是成本低,操作方便,重现性好以及检测下限低。 相似文献
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在0.5mol·L^-1H2SO4的底液中,用玻碳电极作工作电极,然后用循环伏安法和线性扫描伏安法测定苯妥英钠。先在-1.4V富集30s,然后用线性扫描伏安法进行测定。0.3V处的氧化峰电流与苯妥英钠的浓度在2.0×10^-5—3.9×10^-3mol·L^-1范围内呈良好的线性关系。该测定方法的检出下限(3s/N)为8.0×10^-6mol·L^-1。用标准加入法测定回收率范围在96.4%-102.0%,RSD为2.5%(n=4)。该法用于实际样品中苯妥英钠的含量的测定结果与药典法结果一致。 相似文献
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研究了镉离子在PVC-十二烷基苯磺酸钠碳糊修饰电极上的电化学行为,在pH 5.0的B-R缓冲溶液介质中,镉离子在阳极溶出伏安曲线的-0.78 V(vs.SCE)处有一个灵敏的氧化峰.优化了测定条件,建立了测定镉离子的分析方法.峰电流与镉离子的浓度在4.0×10-7~5.0×10-4mol·L-1范围内有良好的线性关系,线性方程为ip=0.1767 0.1055 lg(c×107),相关系数为0.9972,检出限为1.1×10-8mol·L-1.用该法测定了合成水样中的镉离子含量,回收率为98.5%~103%. 相似文献
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聚亚甲基蓝/碳纳米管修饰电极阳极溶出伏安法测定痕量锡 总被引:3,自引:0,他引:3
研究了聚亚甲基蓝/碳纳米管修饰电极通过阳极溶出伏安法测定痕量Sn2+的电分析方法。Sn2+通过与电极表面的亚甲基蓝吩噻嗪环上S和N原子发生螯合作用而富集在电极表面,同时在-1.20 V(vs.SCE)还原成Sn0,当电极电势从-1.20 V向-0.30 V扫描时,被还原的Sn0从电极表面溶出。碳纳米管与亚甲基蓝的协同作用,使得Sn2+在该修饰电极上有良好的响应。Sn2+的溶出峰电流与其浓度在0.2×10-3~0.1 mmol/L浓度范围内呈良好的线性关系,检测限为0.1×10-3mmol/L。 相似文献
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制备了Nafion修饰的丝网印刷电极,并用于同位镀铋膜法测定痕量重金属离子Cd2+。将Nafion溶液滴涂在丝网印刷电极表面制得修饰电极。在含Bi3+的0.1 mol/L醋酸缓冲溶液(pH为4.7)中,将Bi3+与Cd2+共同电沉积在修饰电极表面,再以方波阳极溶出伏安法(SWSV)检测Cd2+的浓度。优化了镀膜条件,考察了Nafion膜厚度及Bi3+浓度对溶出电流的影响。在优化的条件下,0~100μg/L质量浓度范围内Cd2+浓度与溶出峰电流呈现良好的线性关系,检出限为1μg/L,重现性良好,可用于大米中痕量重金属离子Cd2+的快速测定。 相似文献
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运用循环伏安法、线性扫描伏安法等测试技术研究了槲皮素在预处理玻碳电极上的电化学行为,建立了一种直接测定槲皮素的电化学分析方法。结果表明,与裸玻碳电极相比,预处理玻碳电极能显著提高槲皮素的氧化峰电流。在优化的实验条件下,氧化峰电流与槲皮素浓度在1.0×10-7~2.0×10-5mol/L范围内呈良好的线性关系,最低检测限为6.2×10-8mol/L。该方法简便、快捷、准确、灵敏度高。本法用于芦丁水解产物槲皮素的测定,效果良好。 相似文献
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Karla Calfumán Maria Jesús Aguirre Paulina Cañete-Rosales Soledad Bollo Rosa Llusar Mauricio Isaacs 《Electrochimica acta》2011,56(24):8484
This paper describes the electrochemical reduction of nitrite ion in neutral aqueous solution mediated by tetraruthenated metalloporphyrins (Co(II), Ni(II) and Zn(II)) electrostatically assembled onto a Nafion film previously adsorbed on glassy carbon or ITO electrodes. Scanning electron microscope (SEM-EDX) and transmission electron microscopy (TEM) results have shown that on ITO electrodes the macrocycles forms multiple layers with a disordered stacking orientation over the Nafion film occupying hydrophobic and hydrophilic sites in the polyelectrolyte. Atomic force microscopy (AFM) results demonstrated that the Nafion film is 35 nm thick and tetraruthenated metalloporphyrins layers 190 nm thick presenting a thin but compacted morphology. Scanning electrochemical microscopy (SECM) images shows that the Co(II) tetraruthenated porphyrins/Nf/GC modified electrode is more electrochemically active than their Ni and Zn analogues.These modified electrodes are able to reduce nitrite at −660 mV showing enhanced reduction current and a decrease in the required overpotential compared to bare glassy carbon electrode. Controlled potential electrolysis experiments verify the production of ammonia, hydrazine and hydroxylamine at potentials where reduction of solvent is plausible demonstrating some selectivity toward the nitrite ion. Rotating disc electrode voltammetry shows that the factor that governs the kinetics of nitrite reduction is the charge propagation in the film. 相似文献
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Voltammetric determination of paracetamol was carried out at C60-modified glassy carbon electrode, which showed stable response with enhanced selectivity and sensitivity. Limitations of conventional methods, viz., hydrolysis time and interference were also overstepped. Common biological and chemical interferents do not show significant interference in a wide concentration range. A linear calibration plot having correlation coefficient 0.985 was obtained in the range 0.05-1.5 mM paracetamol concentration and the sensitivity of the method has been found as 13.04 μA mM−1. Sweep rate studies indicated that electrode reaction is followed by follow-up chemical reactions. Method described is rapid and has been applied for the determination of paracetamol in different tablets and urine samples with several advantages over other analytical methods. The standard deviation (S.D.) was 5.53% for eight determinations. 相似文献
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The electrochemistry of bisoprolol fumarate (BF) has been investigated by differential pulse voltammetry at a single-wall carbon nanotubes (SWNTs) modified glassy carbon electrode (GCE). The prepared electrode showed an excellent electrocatalytic activity towards the oxidation of BF leading to a marked improvement in sensitivity as compared to bare glassy carbon electrode where electrochemical activity for the analyte cannot be observed. The SWNTs-modified GCE exhibited a sharp anodic peak at a potential of ∼950 mV for the oxidation of BF. Under optimum conditions linear calibration curve was obtained over the BF concentration range 0.01-0.1 mM in 0.5 M phosphate buffer solution (pH 7.2) with a correlation coefficient of 0.9789 and detection limit of 8.27 × 10−7 M. The modified electrode has been applied for the drug determination in human urine with no prior extraction and in commercial tablets. The proposed method has also been validated. 相似文献
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A simple and convenient method is described for voltammetric determination of thiamazole, a commonly used anti-hyperthyroid
drug, based on its electrochemical oxidation at a multi-wall carbon nanotube modified glassy carbon electrode. Under optimized
conditions, the proposed method exhibited acceptable analytical performances in terms of linearity (over the concentration
range from 1.0 × 10−7 to 5.0 × 10−4 mol L−1, r = 0.9983), detection limit (3.0 × 10−8 mol L−1) and reproducibility (RSD = 2.64%, n = 10, for 5.0 × 10−5 mol L−1 thiamazole). To further validate its possible application, the method was used for the quantification of thiamazole in pharmaceutical
formulations and biological fluids. 相似文献
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A glassy carbon (GC) electrode surface was modified with a cadmium pentacyanonitrosylferrate (CdPCNF) film as a novel electrode material. The modification procedure of the GC surface includes two consecutive procedures: (i) the electrodeposition of metallic cadmium on the GC electrode surface from a CdCl2 solution and (ii) the chemical transformation of the deposited cadmium to the CdPCNF films in 0.05 M Na2[Fe(CN)5NO] + 0.5 M KNO3 solution. The modified GC electrode showed a well-defined redox couple due to [CdIIFeIII/II(CN)5NO]0/−1 system. The effects of supporting electrolytes and solution pH were studied on the electrochemical behavior of the modified electrode. The diffusion coefficients of alkali-metal cations in the film (D), the transfer coefficient (α) and the charge transfer rate constant at the modifying film | electrode interface (ks), were calculated in the presence of various alkali-metal cations. The stability of the modified electrode was investigated under various experimental conditions. 相似文献
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运用循环伏安法、线性扫描伏安法及示差脉冲伏安法等测试技术研究了诺氟沙星在多壁碳纳米管修饰玻碳电极上的电化学行为,建立了一种直接测定诺氟沙星的电化学分析方法.结果表明,与裸玻碳电极相比,多壁碳纳米管修饰电极能显著提高诺氟沙星的氧化峰电流.在优化的实验条件下,氧化峰电流与诺氟沙星浓度在1.0×10-7~1.0×10-6mol/L和1.0×10-6~2.5×10-5 moL/L范围呈现良好的线性关系,检出限为3.0×10-8mol/L对1.0×10-5mol/L诺氟沙星溶液平行测定10次的RSD为4.1%.测定了诺氟沙星胶囊中诺氟沙星的含量,结果满意. 相似文献
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A novel modified glassy carbon electrode (GCE) with a binuclear copper complex was fabricated using a cyclic voltammetric
method in phosphate buffer solution. This modified electrode shows very efficient electrocatalytic activity for anodic oxidation
of both dopamine (DA) and ascorbic acid (AA) via substantial decrease in anodic overpotentials for both compounds. Cyclic
voltammetry (CV) and differential pulse voltammetry (DPV) using this modified electrode show two well-resolved anodic waves
for the oxidation of DA and AA in mixed solution, which makes it possible for simultaneous determination of both compounds.
Linear analytical curves were obtained in the ranges 2.0–120.0 μM and 5.0–160.0 μM for DA and AA concentrations by using DPV
methods, respectively. The detection limits were 1.4 × 10−6 M of DA and 2.8 × 10−6 M of AA. This electrode was used for AA and DA determinations in medicine and foodstuff samples with satisfactory results. 相似文献
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A novel method for simultaneous determination of nitrophenol isomers at nano-gold modified glassy carbon electrode has been developed. The gold nanoparticles were directly electrodeposited onto the glassy carbon electrode via a constant potential −0.2 V (vs. SCE) for 60 s from 0.1 mol L−1 KNO3 containing 0.4 g L−1 HAuCl4. The resulting electrode (nano-Au/GCE) was characterized with scanning electron microscopy (SEM). The electrochemistry response of nitrophenol isomers at the nano-Au/GCE was studied. The result indicated that o-, m-, and p- nitrophenol are separated entirely at nano-Au/GCE, and a semi-derivative voltammetric technology was adopted to enhance the determination sensitivity. This modified electrode could be applied to direct simultaneous voltammetric determination of nitrophenol isomers in water samples without preseparation with higher sensitivity. 相似文献