Adsorptive Stripping Voltammetric Determination of Albendazole at a Hanging Mercury Drop Electrode

ABSTRACT

Albendazole is determined by differential-pulse adsorptive cathodic stripping voltammetry at a hanging mercury drop electrode using the reduction peak of its copper(II) complex at ?0.28V at an accumulation potential 0.0V vs. Ag/AgCl electrode. The optimum conditions of pH, accumulation potential and accumulation time were studied. The calibration graph for the determination of albendazole was linear in the range 3.0X10^?8 - 9X10^?7M with a relative standard deviation of 2.8%. The detection limit was 1.0X10^?8M after 180s accumulation at 0.0V. The effect of common excipients and metal ions on the peak height of albendazole was studied. The presence of Cu²⁺ ions forms a stable complex with albendazole which is strongly adsorbed at the mercury electrode surface. The method was applied to the determination of the drug in commercially available dosage forms.     

吸附溶出伏安法测定苯胺的研究

在酸性介质中,苯胺与亚硝酸根离子和盐酸萘乙二胺反应生成玫瑰红色偶氮染料,该染料在汞电极上具有良好的吸附性能,并且在氨性缓冲介质中可在汞电极上还原,于－０．５５Ｖ左右产生一灵敏的吸附极谱波。据此,建立了吸附溶出伏安法测定苯胺的方法。当吸附富集时间为３ｍｉｎ时,该法的检测下限为５×１０－９ｍｏｌ／Ｌ,比分光光度法降低了近两个数量级。应用本方法测定了废水中的苯胺,结果满意。     

吸附溶出伏安法测定普罗帕酮的研究

在pH 6.47的磷酸盐缓冲溶液中,可得到普罗帕酮的吸附溶出峰。峰电位为-1.38V(vs.Ag/AgCl),富集1min,溶出峰电流与普罗帕酮浓度在8.0x10~(-9)～7.0x10~(-7)mol/L范围内呈线性关系。富集4min检测下限为3.0×10(-10)mol/L。该法用于测定普罗帕酮制剂及人血清中的痕量普罗帕酮,均得到了满意的结果,并探讨了电极反应过程机理。     

吸附溶出伏安法测定痕量砷的研究

在稀盐酸底液中,砷(Ⅲ)与吡咯烷二硫代甲酸铵(APDC)形成的络合物在悬汞电极(HME)上有良好的吸附溶出行为,于—0.53V(vs. SCE. )处有一灵敏的二次导数溶出峰。在1.3×10~(-9)—2.6X10~(-7)mol/As(Ⅲ)浓度范围内,峰高与As(Ⅲ)浓度有良好的线性关系,检出限为1.3×10~(-10)~mol/L。曾用本法测定两种标样以及茶叶中的砷,结果满意。本文还研究了电流性质及电极过程机理。     

Determination of Folic Acid at a Bismuth Film Electrode by Adsorptive Stripping Voltammetry

This article reports a new simple and sensitive method for the determination of folic acid by adsorptive stripping voltammetry. The method is based on the accumulation of folic acid at a bismuth film plated in situ on a glassy carbon substrate. In order to stabilize bismuth ions, sodium potassium tartrate was added to the supporting electrolyte. The bismuth film formation and folic acid accumulation conditions were optimized and measurements were carried without solution deaeration. The calibration graph was linear from 5 × 10^?10 to 2 × 10^?8 mole per liter with an accumulation time of 180 seconds with a limit of detection of 2 × 10^?10 mole per liter. The relative standard deviation for 5 × 10^?9 mole per liter of folic acid was 3.1 percent (n = 5). The method was successfully applied for determination of folic acid in pharmaceutical preparations.     

固态汞合金电极吸附伏安法测定酪氨酸

采用白合金粉与汞混合制成汞合金糊,涂布在固体石蜡碳糊电极表面,固化后制得固态汞合金电极,并首先应用于酪氨酸的测定。在含Co2 的pH 9.2的硼砂-NaOH底液中,用线性扫描伏安法在-0.80~-1.30V范围内进行扫描,酪氨酸于-1.05 V出现灵敏的还原峰,酪氨酸的浓度与峰电流在1.0×10-7~1.0×10-5mol/L范围内呈线性关系。该法已用于复方氨基酸注射液中酪氨酸含量的测定,加标回收率达96%~102%。该电极既保留了汞电极的优点,又避免了汞电极有毒、使用不方便的缺点。     

氟哌啶醇的吸附伏安法研究

于NH_3-NH_4Cl底液中,氟哌啶醇(Hal)在悬汞电极上有一灵敏的还原蜂。EPC为-1.55V(vs饱和Ag/AgCl电极),其线性扫描吸附伏安法的线性范围为5.0×10~(-9)～9.0×10~(-7)mol/L。最低检测限为2.0×10~(-9)mol/L。测定了用药患者的尿样及针剂,片剂中Hal的含量,结果满意。对Hal在汞电极上的电化学性质,特别是吸附性进行了探讨。     

吸附溶出催化伏安法测定痕量锗

利用吸附溶出伏安法、极谱催化法测定痕量锗已有报道。但将吸附溶出伏安法与极谱催化法结合进行测定,尚未见报道。我们选择适当的体系和配位体3,4-二羟基苯甲醛(DHB)及氧化剂钒(V),首先使Ge(Ⅳ)-DHB络合物在悬汞电极上于一定电位处吸附富集一定时间,然后电位向负的方向扫描。当达到Ge(Ⅳ)-DHB络合物的还原电位时,Ge(Ⅳ)还原     

Determination of Platinum with Thiosemicarbazide by Catalytic Adsorptive Stripping Voltammetry (AdSV)

This work describes a very sensitive and selective voltammetric procedure for the determination of platinum. Instead of commonly used hydrazine, thiosemicarbazide as a component of supporting electrolyte was applied. The method is based on adsorption of platinum‐thiosemicarbazone complex, formed in situ in voltammetric cell from thiosemicarbazide and formaldehyde, coupled with a hydrogen catalytic reaction at a hanging mercury drop electrode. The linear relation between platinum concentration and height of analytical signal was observed up to 1.5×10^?9 mol L^?1 with the detection limit calculated as 1.5×10^?13 mol L^?1 (3 s of the blank) after 50 s of accumulation time. The effect of various interferences from other ions was studied. Described method was applied for platinum determination in hydroponically cultivated plants after microwave decomposition.     

New Protocol for Determination of Rifampicine by Adsorptive Stripping Voltammetry

For determinations of organic compounds by adsorptive stripping voltammetry till now the same material of the electrode has been used for the accumulation and stripping steps. This paper describes a new protocol for extending the range of organic compounds, which can be determined by adsorptive stripping voltammetry. In the proposed procedure the accumulation step was performed on the electrode modified by a lead film, which assures adsorption of the studied species on the modified electrode and then the stripping step of the accumulated substance was performed on the support of the lead film electrode. As an example rifampicine was accumulated by adsorption at the lead film electrode while in the stripping step lead film and then the accumulated rifampicine were oxidized at a glassy carbon electrode. Using an acetate buffer as a supporting electrolyte a calibration graph for rifampicine in the range from 2.5×10^?10 to 1×10^?8 mol L^?1 was obtained. The detection limit for rifampicine following 60 s accumulation time was equal to 9×10^?11 mol L^?1. The obtained detection limit was comparable or lower than reported previously for other stripping voltammetric procedures. The proposed procedure was applied to rifampicine determination in pharmaceutical preparation.     

大黄素的吸附溶出伏安研究

研究了大黄素在甲醇、二氧六环和水的混合溶剂中以１％硼砂为支持电解质在静汞电极上的吸附伏安行为。建立了用微分脉冲吸附溶出伏安法测定其含量的新方法。在－０３０Ｖ（ｖｓＡｇ／ＡｇＣｌ）电位下吸附富集，可得一灵敏的还原溶出峰，峰电位－０７５Ｖ，浓度在５×１０－８～５×１０－９ｍｏｌ／Ｌ范围内与峰电流具有良好的线性关系，最低检出限为１×１０－９ｍｏｌ／Ｌ。该法用于含有大黄素体系的测定简便、快速、可靠。     

Determination of Trace Amounts of Copper by Adsorptive Stripping Voltammetry

ABSTRACT

A technique is presented for the determination of trace amounts of copper(II) by adsorptive cathodic stripping voltammetry. The procedure is based on adsorptive accumulation of copper(II)-Alizarin Red S (ARS) complex on a hanging mercury drop electrode, followed by a stripping voltammetric measurement of the reduction current of the adsorbed complex at -0.16 V (vs. Ag/AgCl). The height of the copper -ARS reduction peak is linearly dependent upon the copper(II) concentration between 0.2-15 and 15-500 ng.ml^?1. The detection limit of the technique is 0.05 ng.ml^?1 copper(II) for a collection time of 1 minute. The method is free from most interferences. The procedure has been successfully applied to the determination of trace amounts of copper(II) in some analytical grade salts.     

吸附溶出伏安法测定水中痕量镉

报道了测定痕量镉的一种新方法．在０．０１ｍｏｌ／ＬＨＡｃ－０．０１ｍｏｌ／ＬＮａＡｃ－１．２×１０－５ｍｏｌ／Ｌ乙醛酸缩氨基硫脲（ＧＡＴＳＣ）体系中，Ｃｄ－ＧＡＴＳＣ产生一灵敏的吸附还原波，波的峰电位是－０．４３Ｖ（ｖｓ·ＳＣＥ），峰电流与镉的浓度在１．０×１０－８～８．０×１０－７ｍｏｌ／Ｌ范围内成直线关系．此法用于测定水中痕量镉，结果令人满意。     

Determination of Sulpiride by Linear Sweep Stripping Voltammetry at a Mercury Electrode

This paper reports the electrochemical properties of sulpiride at a mercury electrode,especially its adsorptive characteristic,Sulpiride dissolved in a supporting electrolyte of a McIlvaine buffer at pH 6.8 represents a sensitive and well defined reduction wave by linear sweep stripping voltammetry.This method is based on the pre-concentration and the reduction of sulpiride at a hung mercury drop electrode.The reduction peak potential is -1.72V(vs.Ag-AgCl) and the peak current is proportional to the concentration of sulpiride in the range of 0.1-0.6 μg/mL.The detection limit is 0.0250μg/mL obtained under the experimental conditions selected in this work.The electrochemical properties of this system were investigated.and the proposed method was applied to the determination of sulpiride in pharmaceutical tablets with satisfactory results,It was compared well with the UV spectrophotometric method,showing a superior sensitivity.     

铜的腺嘌呤络合物在悬汞电极表面上的吸附形态和氧化还原行为

本文详细地研究了铜的腺嘌呤（Ａｄｅ）络合物在悬汞电极（ＨＭＤＥ）表面上的吸附形态和伏安行为。实验结果揭示了单层吸附饱和之前有Ｃｕ＾＋Ａｄｅ，Ｃｕ２＾＋（Ａｄｅ）２形态的共吸附作用，随着电极表面的吸附浓度增长，Ａｄｅ络合物分子有从平面向垂直吸附的定向作用。哦的多层吸附和聚合作用发生在吸附分子垂直定向以后。本文还测定了有关电极过程的动力学参数。     

Determination of Pb and Cu by Anodic Stripping Voltammetry Using Glassy Carbon Electrodes Modified with Mercury or Mercury-Nafion Films

 Two different approaches for the modification of glassy carbon electrodes using a mercury film and mercury-nafion are compared. The mixture of mercury(II) chloride solution with a nafion solution diluted in ethanol is used to coat the polished glassy carbon surface. The modified working electrodes are compared when measuring Pb and Cu in real seawater samples. An optimisation of the parameters during the formation of the films was done to obtain well-defined stripping peaks. The type of inert supporting electrolyte and the pH play an important role on the sensitivity of the measurement. Results for Pb and Cu determinations show the advantages of Hg-nafion modification as an alternative method. These advantages include a shorter modification time, the avoidance of Hg solutions during the formation of the Hg film and an improved sensitivity for Pb determination. Received March 16, 1999. Revision April 24, 2000.     

Indirect Determination of Trace Copper(II) by Adsorptive Stripping Voltammetry with Zincon at a Carbon Paste Electrode

Traces of copper(II) can be determined by adsorptive stripping voltammetry using 2‐carboxy‐2′‐hydroxy‐5′‐sulfoformazyl benzene (Zincon) as complex forming reagent. First in phosphate buffer pH 6.4, copper(II)‐Zincon complex was adsorbed on carbon paste electrode (CPE) with an accumulation potential of 0.6 V. Following this, adsorbed complex was oxidized and detected by differential pulse voltammetric (DPV) scan from 0.6 to 1.0 V. The effective parameters in sensor response were examined. The detection limit (DL) of copper(II) was 1.1 μg/L and relative standard deviations (RSDs) for 10 and 200 μg/L Cu(II) were 1.81 and 1.03%, respectively. The calibration curve was linear for 2–220 μg/L copper(II). The resulting CPE does not use mercury and therefore, has a positive environmental benefit. The method, which is reasonably sensitive and selective, has been successfully applied to the determination of trace amount of copper in water and human hair samples.     

Cathodic Adsorptive Stripping Voltammetry for Estimation of the Forest Area Pollution with Nickel and Cobalt

 Necessary conditions were established for simultaneous nickel and cobalt determination in environmental samples, such as oak wood and soil, based on cathodic adsorptive stripping voltammetry. Ni(II) and Co(II), complexed with dimethylglyoxime, were determined using a hanging mercury drop electrode. Optimum conditions were found to be: accumulation time 90 s, accumulation potential −0.80 V vs. SCE, supporting electrolyte 0.2 mol dm⁻³ ammonia-ammonium chloride buffer (pH = 9.4) + 0.05 mol dm⁻³ NaNO₂ and dimethylglyoxime 2 × 10⁻⁴ mol dm⁻³. A linear current-concentration relationship was observed up to 7.51×10 ⁻⁷ mol dm⁻³ for Ni(II) and 7.0 × 10⁻⁷ mol dm⁻³ for Co(II). Excess amounts of zinc(II) interfering with cobalt peaks were masked by complexation with EDTA. Wood and soils were mineralized by applying a microwave digestion system, using the mixtures H₂O₂ + HNO₃ or HNO₃ + HF, respectively. The developed procedure was tested by analysing international reference materials (BCR 62 Olive Leaves and GBW 08302 Tibet Soil). The developed procedure was used to determine pollution of oak stand with nickel and cobalt in different regions of Poland. Received August 10, 2000. Revision May 22, 2001.     

Determination of Trace Vanadium by Adsorptive Stripping Voltammetry at a Carbon Paste Electrode

A method for the voltammetric determination of vanadium using a carbon paste electrode (CPE) was described. The new procedure is based on the adsorptive accumulation of the V(V)‐alizarin red S(ARS) complex onto the surface of the CPE, followed by the electrochemical reduction of adsorbed species. The optimal experimental conditions include the use of 0.10 mol/L acetate buffer (pH 5.1), 1.0×10^?5 mol/L ARS, an accumulation potential of ?0.10 V (versus SCE), an accumulation time of 2 min, a scan rate of 200 mV/s and a second‐order derivative linear scan mode. The reduction peak for the complex appears at ?0.52 V. The peak current is proportional to the concentration of V(V) over the range of 0.10–15.0 μg/L, and the detection limit is 0.04 μg/L for a 2 min adsorption time. The relative standard deviations(n=8) for 2.0 and 0.50 μg/L V(V) are 3.1 and 4.7%, respectively. The proposed method was applied to the determination of vanadium in water samples.