铋膜电极阳极溶出伏安法测定血样中的锌

采用阳极溶出伏安法用玻碳电极同位镀铋膜测定血样中的锌。实验结果表明,在0.20mol/L的支持电解质KSCN(pH=2.80)中于-1.00V下搅拌富集2min后,进行阳极极化扫描,可获一灵敏的阳极溶出峰,利用该方法测定锌的检出限为1.0×10-11mol/L,线性范围为5～25μmol/L。锌标准溶液测定结果的相对标准偏差为3.14%(n=11),加标回收率为95.6%～104.8%。     

聚乙烯醇对锌镉铅溶出增敏作用及应用

在０．０５ｍｏｌ／Ｌ（ｐＨ６．５）乙二妥－盐酸介质中,聚乙烯醇－１２４ＰＶＡ－１２４）对锌,镉,铅的电位溶出有显著的增敏作用。当富集６０ｓ时,其检出限均达６．０μｇ／Ｌ,线性范围：锌０．６－３５μｇ／Ｌ,镉０．６－４５μｇ／Ｌ,铅０．６－５０μｇ／Ｌ。标准加入回收率为９２．４％－１１０％。ＲＳＤ（ｎ－４）〈７．０％。     

铜膜差分脉冲阳极溶出伏安法测定药物中铋的含量

研究了铜膜电极代替汞膜电极测定重金属铋的差分脉冲溶出伏安法。实验了同位镀膜法测定铋的条件。在最佳实验条件下,Bi3+浓度在5×10-8~2×10-5mol/L范围内,其溶出峰峰高与浓度呈线性关系,检出限达到1×10-8mol/L。测定了一些药物中铋的含量,结果准确。     

聚乙烯醇对电位溶出测定砷(Ⅲ)的增敏作用

1 引言 砷对生物体及环境等危害极大,因此对砷的测定极为重要。现有的砷斑法及银盐法等因灵敏度低,往往不能满足工作要求。而氢化物原子吸收法及荧光法灵敏度虽高,但仪器昂贵,一时难以普及。近年来有关砷的溶出分析虽有报道,但利用表面活性剂的增敏作用未曾有人研究。本文经实验筛选发现在1.5mol/L HCl介质中,非离子表面活性剂聚乙烯醇-124(PVA-124)对砷的金膜电位溶出有极强的增敏作用。当在—0.40V下电沉积100s,用同位镀金样品标准加入法测量时,食品及天然水中砷(Ⅲ)的检出限分别高达4.0μg/kg及0.6     

预镀铋膜阳极溶出伏安法测定废水中微量铅和镉

本文采用预镀铋膜法修饰玻碳电极,并用该电极对废水中微量铅和镉同时进行了阳极溶出伏安法测定,研究了预镀铋膜测定铅和镉的条件。实验结果表明:铅和镉在铋膜电极上可得到灵敏的电位溶出峰,峰高和溶出电位与汞膜电极法相近,使用预镀铋膜电极可避免使用汞电极带来的环境污染。     

丁二酮肟修饰碳糊电极阳极溶出伏安法测定痕量铋

报道了用丁二酮肟修饰碳糊电极测定微量铋的电分析方法。Bi~(3+)通过与电极表面的丁二酮肟作用而富集在电极表面,同时在-0.40 V(vs.SCE)还原成零价,当电极电势从-0.40 V向0.40 V扫描时,被还原的铋从电极表面溶出,在0.03 V出现一个十分灵敏的阳极溶出峰。优化了各种实验参数,如支持电解质的选择及pH值、丁二酮肟的用量、富集电位及时间等。修饰电极测定铋的线性范围为1×10~(-9)～1×10~(-6)mol/L。富集6 min后检出限可达4×10~(-10)mol/L。该方法简便快速,灵敏度高,分析成本低廉,并成功应用于实际水样中微量铋的测定。     

铋膜电极溶出伏安法测定食品中痕量重金属

以铋膜电极为工作电极,采用微分脉冲阳极溶出伏安法直接测定食品样品中痕量铅、镉和锌。在富集电位-1.4V,富集时间180s,铋膜质量浓度150μg·L-1的条件下,铋膜电极对铅、镉和锌的氧化溶出具有良好的电化学响应。铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)的质量浓度在5.0~40μg·L-1的范围内与其阳极溶出峰电流呈线性关系,铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)的检出限(3S/N)分别为0.80,0.65,0.58μg·L-1。对25μg·L-1铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)溶液用铋膜电极连续测定15次,相对标准偏差分别为6.2%,5.1%,7.1%。方法应用于食品中痕量重金属的测定,测定结果与石墨炉原子吸收光谱法的测定值相符。     

铋膜电极电位溶出法测定痕量铅、镉、锌

研究了用铋膜电极替代汞膜电极测定痕量重金属元素铅、镉和锌的电位溶出法。实验了同位镀铋膜及测定重金属特别是痕量铅的条件。实验结果表明：铅、镉、锌在铋膜电极上可得到灵敏的电位溶出峰，峰高和溶出电位与汞膜电极法相近，使用铋膜电极可避免使用汞电极带来的环境污染。利用铋膜电极电位溶出法测定了水样及血样中痕量铅的含量。     

Nafion汞膜修饰电极用于阳极溶出伏安法测定痕量铋的研究

本文报道了Nafion汞膜修饰电极及其用于阳极溶出伏安法测定未处理尿样,水样及土样中痕量铋的研究。样品中常共存的Pb(Ⅱ)、Sb(Ⅲ )等19种阳离子及尿样中共存的有机物在实验条件下不干扰。本法不仅选择性好,而且灵敏度也较高。线性范围为2×10~(-10)～1×10~(-7)mol/L。回收率为94～105％。     

Square-Wave Anodic Stripping Voltammetry (SWASV) for the Determination of Ecotoxic Metals,Using a Bismuth-Film Electrode

This article reviews the use of square wave anodic stripping voltammetry for the simultaneous determination of ecotoxic metals (Pb, Cd, Cu, and Zn) on a bismuth-film (BiFE) electrode. The BiFE was prepared in situ on a glassy-carbon electrode (GCE) from the 0.1 mol L^?1 acetate buffer solution (pH 4.5) containing 200 µg L^?1 of bismuth (III). The addition of hydrogen peroxide to the electroanalytical cell proved beneficial for the interference-free determination of Cu (II) together with zinc, lead, and cadmium, using the BiFE. The experimental variables were investigated and optimized with the view to apply this type of voltammetric sensor to real samples containing traces of these metals. The performance characteristics, such as reproducibility, decision limit (CC_a), detection capability (CC_β), sensitivity, and accuracy indicated that the method holds promise for trace Cu²⁺, Pb²⁺, Cd²⁺, and Zn²⁺ levels by employment of Hg-free GCE with SWASV. CCa, and CCβ were calculated according to the Commission Decision of 12 August 2002 (2002/657/EC). Linearity was observed in the range 20–280 µg L^?1 for zinc, 10–100 µg L^?1 for lead, 10–80 µg L^?1 for copper, and 5–50 µg L^?1 for cadmium. Using the optimized conditions, the stripping performance of the BiFE was characterized by low limits of detection (LOD). Finally, the method was successfully applied in real as well as in certified reference water samples.     

Anodic Stripping Voltammetry Using a Vibrating Electrode

This work proposes a vibrating microwire electrode as working electrode in stripping voltammetry. The vibration was found to maintain a constant and thin (1–2 μm) diffusion layer during the deposition step. The electrode vibration eliminated the need for external stirring of the solution, thus facilitating in situ detection in the environment. The vibration was effected by fixing a low‐voltage (3 V), asymmetric, electrical rotor to the working electrode (a gold microwire of either 5 or 25 μm). The sensitivity of the vibrated electrode was ca. 22×greater than stationary. Measurements of copper (4 nM) by anodic stripping voltammetry using the vibrating electrode had a low standard deviation (1% for n=6) indicating that the diffusion layer had only minor variability. The agitation mechanism was unaffected by water moving at >2 m s^?1 and by water pressure equivalent to a depth of >40 m, indicating its suitability for in situ measurements. The vibrating probe was used for in situ detection of copper by anodic stripping voltammetry to a depth of 6 m. Using a 5 min deposition time, the limit of detection for labile copper was 38 pM.     

Zinc Detection in Serum by Anodic Stripping Voltammetry on Microfabricated Bismuth Electrodes

Zinc (Zn) homeostasis is required for a functional immune system. Critically ill patients often exhibit decreased Zn serum concentrations and could potentially benefit from Zn supplementation as a therapeutic strategy. However, the conventional approaches to monitoring Zn are time consuming and costly. This work reports on detection of Zn by anodic stripping voltammetry (ASV) on bismuth electrodes in a microfabricated electrochemical cell. The working potential window of the electrodeposited bismuth film electrode was investigated by cyclic voltammetry, while square wave ASV was used for measuring Zn in acetate buffer and blood serum. Conditions critical to sensing, such as preconcentration potential, preconcentration time, and buffer pH, were optimized for Zn detection. The sensor was successfully calibrated with pH 6 acetate buffer in the physiologically‐relevant range of 5 µM to 50 µM Zn and exhibited well‐defined and highly repeatable peaks. The sensor was used to demonstrate measurement of Zn in blood serum digested in HCl. The results of this work show that Zn detection in serum is possible with smaller sample volumes (µL vs. mL) and faster turnaround time (hours vs. days) as compared with the conventional spectroscopic methods.     

Nafion修饰电极同位镀金膜阳极溶出伏安法测定痕量砷

金膜电极阳极溶出伏安法测定痕量砷已有报道,但铜、锑、铋存在严重干扰。本文采用Nafion修饰电极同位镀金膜阳极溶出伏安法测定痕量砷,大大提高了其选择性,铜、锑、铋分别为砷含量的6倍,3倍和6.5倍以下时,不干扰测定;测定灵敏度也较同位镀金膜电极时高。本法应用于标钢和黄河底泥中砷含量的测定,均获得满意结果。     

Anodic Stripping Voltammetry: Arsenic Determination in Ancient Bone Samples

Abstract

A highly sensitive method for the determination of arsenic (As) content in ancient bone samples was studied using a gold tipped rotating disc electrode and differential pulse anodic stripping voltammetry. Factors affecting sensitivity and precision, including electrolyte concentration, deposition potential, deposition time, and rotation rate were investigated. Electroinactive As(V) was reduced to As(III) by HCl 30% w/v prior to electroanalytical measurements. For a deposition time of 120 sec, the lowest detection limit (LOD) for arsenic was 1.078 µg/L. Optimized working conditions are defined as a deposition potential of ?1200 mV with a deposition time of 120 sec, 10 M HCl as the supporting electrolyte, and a rotation rate of 2000 rpm. Results of electroanalytial measurements in ancient bone samples are compared with those obtained from the hydride generation atomic absorption spectroscopy (HG‐FAAS) analysis. Analytical relevancy of the two methods was then compared with the aid of statistical data treatment.     

碳纤维束汞膜电极二次微分阳极溶出伏安法测定锌中微量铅

本文提出了碳纤维束汞膜电极二次微分阳极溶出伏安法测定锌中微量铅的方法，对溶解氧，扫描速度，电极清洗时间，富集电位和时间及酸度的影响作了讨论。方法的线性范围为１．９－８０μｇ／Ｌ；检测下限达到１．９μｇ／Ｌ；对国家保证参考物质锌样中铅的测定，相对标准偏差和相对误差分别为２．６％和０．６５％，结果令人满意。     

聚乙烯醇修饰电极的研制及应用

本文提出用玻碳电极为基体制作聚乙烯醇(PVA)修饰电极。研究了铜在该电极上的阳极溶出伏安特性。探讨了电极修饰及其作用机理。电极可用于水中痕量铜的测定,灵敏度比未修饰玻碳电极提高一个数量级以上。     

Determination of Thiols and Disulfides in Whole Blood and Its Fractions by Anodic Stripping Voltammetry and Anodic Stripping Voltammetric Titration

SH‐ and SS‐groups content and their ratio is one of the most important factors of organism antioxidant system. Change in ratio of thiols to disulfides can serve as an indicator of oxidative stress. Anodic stripping voltammetry and anodic stripping voltammetric titration (direct and reverse variants) methods are proposed for determination of thiols and disulfides concentration. Disulfides are preliminary reduced with sodium sulfite. Ag⁺+RSH→AgSR+H⁺ reaction is used to provide the information. Unreacted silver ions concentration is determined by anodic stripping voltammetry method using platinum working electrode. Calibration free method is suggested. The possibilities of express analysis of blood and its fractions are described. Reliability of results and accuracy are confirmed by model solutions analysis and recovery study of whole blood and its fractions. Results of whole blood, erythrocyte mass, plasma and serum taken from different groups of patients' investigations are given, that demonstrate perspectives of the application methods in clinical practice.     

Simultaneous Determination of Pb and Cd Traces in Water Samples by Anodic Stripping Voltammetry Using a Modified GC Electrode

The determination of Pb and Cd with a Nafion‐modified glassy carbon electrode and Cu‐DPABA complex (Cu‐DPABA–NA/GCE; DPABA is methyl 3,5‐bis{bis‐[(pyridin‐2‐yl)methyl]amino}methyl‐benzoate) as an alternative electrode for anodic stripping voltammetry was described. Pb and Cd were accumulated in acetate buffer pH 4 at a potential of ?1.4 V (vs. Ag/AgCl electrode) for 120 s followed by a DPASV scan from ?1.2 to ?0.2 V. Under optimum conditions the calibration curves were linear in the range of 4.8×10^?9–5.0×10^?5 and 5.0×10^?9–5×10^?5 mol L^?1 for Pb and Cd, respectively. Detection limits were 1.8×10^?9 and 1.2×10^?9 mol L^?1 for Pb and Cd, respectively. Different parameters and conditions, such as membrane ingredients, accumulation time, potential and pH value were optimized. A study of interfering substances was also performed. A significant increase in current was achieved at the modified electrode in comparison with the bare glassy carbon electrode. The validation of the proposed method was made by Pb and Cd determination in the certified reference material Groundwater CRM 610 (BCR, Community Bureau of Reference, Brussels, Belgium). The electrode was successfully applied for determination of Pb and Cd in river water with a high content of organic contaminants without any pretreatment.