Highly sensitive and selective anodic stripping voltammetric procedure of As(III) determination following double deposition and double stripping steps mode in combination with a flow system.

Double deposition and double stripping steps mode was used for the first time in combination with a flow system for anodic stripping voltammetric determination of As(III) ions. The proposed way of the voltammetric measurements leads to a decrease of the detection limit as compared to the values obtained using a traditional three-electrode system thanks to an initial preconcentration of the analyte on the first working electrode as well as the significant increase of the selectivity of As(III) determination thanks to the application of a flow system. Optimization of the analytical procedure was performed.

Adsorptive Stripping Voltammetric Quercetin Determination in Pharmaceuticals and Urine Samples Using a Long Service-Life Array of Carbon Composite Microelectrodes.

This article presents for the first time a new working electrode with a long service life- the bismuth-plated array of carbon composite microelectrodes for the simple, fast and sensitive determination of quercetin by adsorptive stripping voltammetry. The main experimental conditions were selected. The calibration graph was linear from 1 × 10 to 2 × 10 mol L with an accumulation time of 60 s.

Anodic Stripping Voltammetric Procedure of Thallium(I) Determination by Means of a Bismuth-Plated Gold-Based Microelectrode Array.

This article presents a new working electrode based on a bismuth-plated, gold-based microelectrode array, which is suitable for determining thallium(I) species using anodic stripping voltammetry (ASV). It allowed a significant increase in the sensitivity as compared to other voltammetric sensors. The main experimental conditions and the instrumental parameters were optimized.

A Novel Eco-Friendly and Highly Sensitive Solid Lead-Tin Microelectrode for Trace U(VI) Determination in Natural Water Samples.

For the first time a solid state lead-tin microelectrode (diameter ϕ 25 µm) was utilized for U(VI) ion determination by adsorptive stripping voltammetry. The described sensor is characterized by high durability, reusability and eco-friendly features, as the need for using lead and tin ions for metal film preplating has been eliminated, and consequently, the amount of toxic waste has been limited. The advantages of the developed procedure resulted also from the utilization of a microelectrode as a working electrode, because a restricted amount of metals is needed for its construction.

Application of a solid lead microelectrode as a new voltammetric sensor for adsorptive stripping voltammetry of U(VI).

For the first time solid lead microelectrode was utilized for analytical purposes: the article reports on its application for adsorptive stripping voltammetric determination of U(VI) ions. The proposed solid metal microelectrode of a diameter of 25 μm contains about 30 μg of metallic lead that significantly restricts amount of toxic lead introduced into the environment in comparison to lead film equivalents. The potential window of the proposed sensor was checked by means of cyclic voltammetry.

Anodic stripping voltammetry following double deposition and stripping steps: Application of a new approach in the course of lead ion determination.

A new approach of double deposition and stripping steps was proposed in the course of anodic stripping lead ion determination in order to decrease the detection limit. Two bismuth film working electrodes differing in their surface area and mounted in one body were used for the measurements. In short, an ensemble of microelectrodes was centrally mounted in the electrode of a large surface area.

A simple stripping voltammetric method for the determination of a new anticancer prodrug in serum.

The determination of ethyl [4-oxo-8-(3-chlorophenyl)-4,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl]acetate (ETTA), a new anticancer prodrug, using adsorptive stripping voltammetry (AdSV) was described for the first time. This method is based on adsorptive/reductive behaviour of ETTA at an in situ plated bismuth film electrode (BiFE) as a sensor. A number of experimental variables (e.

Determination of trace Se(IV) by anodic stripping voltammetry following double deposition and stripping steps.

A procedure of Se(IV) determination by anodic stripping voltammetry using two deposition and stripping steps at gold electrodes was proposed. A well-defined stripping peak of selenium was obtained at potential 0.9 V.

Determination of As(III) by anodic stripping voltammetry following double deposition and stripping steps at two gold working electrodes.

The double deposition and stripping steps were proposed to minimize interference and increase the sensitivity in anodic stripping voltammetry of As(III). Two working electrodes of drastically different surface areas were used for the measurements. Arsenic was first deposited at the gold film electrode of a large surface area.

An adsorptive stripping voltammetry procedure for ultra-trace determination of U(VI) using double accumulation step on two lead-film working electrodes.

We report a very sensitive stripping voltammetric procedure for determination of ultra-trace quantity of U(VI) in water samples. A very low detection limit was achieved owing to the application of a new construction of the voltammetric electrode cell with two built-in working electrodes that differed significantly in their surface area. The procedure was based on the double adsorptive accumulation of the U(VI)-cupferron complex onto two lead film working electrodes.

Determination of Cr(VI) in the presence of high excess of a Cr(III) by adsorptive stripping voltammetry.

A sensitive and highly selective adsorptive stripping voltammetric procedure for determination of traces of Cr(VI) is presented. Cr(III) interference was minimized due to (a) partial adsorption of this form of chromium from the sample on aluminum oxide and (b) using as a detection method adsorptive stripping voltammetry, which allows for selective determination of Cr(VI) in the presence of a 100-fold excess of Cr(III). The procedure can be used for determination of Cr(VI) even in the presence of a 10,000-fold excess of Cr(III).

Analysis of organic compounds using an in situ plated lead film electrode.

For many years mercury electrodes were commonly used in stripping voltammetry for determination of organic compounds, owing to their high sensitivity, reproducibility and renewability. However, because of the toxicity of mercury, alternative (less toxic) electrode materials are searched. The review describes recent results regarding adsorptive stripping voltammetric determination of trace concentration of biologically active organic substances using an in situ plated lead film electrode (LFE).

Development of a simple and fast voltammetric procedure for determination of trace quantity of Se(IV) in natural lake and river water samples.

A simple and fast cathodic stripping voltammetric procedure for determination of trace quantity of Se(IV) in natural samples containing high concentrations of surfactants and humic substances was developed. The procedure exploiting selenium accumulation (from sample solution spiked with 0.1 mol L(-1) HClO(4) and 4 x 10(-4)mol L(-1) Cu(NO(3))(2)) as Cu(2)Se was employed as the initial method.

Voltammetric method for the determination of sildenafil citrate (Viagra) in pure form and in pharmaceutical formulations.

A highly sensitive and simple voltammetric method for the determination of sildenafil citrate (SC) was developed. The method is based on the accumulation by adsorption of SC on a lead film modified glassy carbon electrode (LF/GCE) and then the reduction of SC throughout the stripping step. During the determinations of SC at the lead film electrode three adsorptive stripping voltammetric peaks at -1.

Evaluation of ammonia buffer containing EDTA as an extractant for Cr(VI) from solid samples.

A novel procedure for the extraction of soluble, sparingly soluble and insoluble Cr(VI) from solid samples was presented. EDTA was added to an ammonia buffer commonly used only for the extraction of soluble and sparingly soluble Cr(VI). In the course of extraction in an ultrasonic bath cations which form insoluble chromates are complexed with EDTA while Cr(VI) is transferred to the solution.

Determination of traces of cobalt in the presence of nioxime and cetyltrimethylammonium bromide by adsorptive stripping voltammetry.

A sensitive method of Co(II) determination by adsorptive stripping voltammetry is presented. The method exploits the enhancement of cobalt peak current observed in the system Co(II)-nioxime-cetyltrimethylammonium bromide-piperazine-N,N'-bis(2-ethanesulfonic acid). The calibration plot for an accumulation time of 60s is linear from 5 x 10(-11) to 3 x 10(-9)molL(-1).

Adsorptive stripping voltammetric determination of trace concentrations of molybdenum at an in situ plated lead film electrode.

An in situ plated lead film electrode has been applied for adsorptive stripping voltammetric determination of trace concentrations of molybdenum in the presence of Alizarin S. The procedure is based on the preconcentration of the molybdenum-Alizarin S complex at an in situ plated lead film electrode held at -0.6 V (versus Ag/AgCl), followed by a negatively sweeping square wave voltammetric scan.

Application of lead film electrode for simultaneous adsorptive stripping voltammetric determination of Ni(II) and Co(II) as their nioxime complexes.

An adsorptive stripping voltammetric (AdSV) procedure for simultaneous determination of Ni(II) and Co(II) in the presence of nioxime as a complexing agent at an in situ plated lead film electrode was described. The Co(II) signal was enhanced by exploitation of the catalytic process in the presence of nitrite. Ni(II) and Co(II) signals are better separated than in the case of bismuth film electrodes.

Determination of uranium by adsorptive stripping voltammetry at a lead film electrode.

An adsorptive stripping voltammetric procedure for the determination of U(VI) at an in situ plated lead film electrode is described. The U(VI) complex with cupferron was accumulated from an acetate buffer solution of pH 4.2 at the potential -0.

Application of gallium film electrode for elimination of copper interference in anodic stripping voltammetry of zinc.

For elimination of copper interference in anodic stripping determinations of zinc at mercury and bismuth film electrodes gallium ions are usually added to the supporting electrolyte. In the presented studies novel ex situ formed gallium film electrode was applied for this purpose. The proposed electrode is less toxic than mercury one while the detection limit for zinc was lower than for bismuth film electrode following the same deposition time.

Extraction and determination of hexavalent chromium in soil samples.

A procedure for the extraction of Cr(VI) from solid soil-like samples was presented in which the complexing properties of diethylenetriaminepentaacetic acid (DTPA) were exploited to extract insoluble compounds of Cr(VI). A concentration of DTPA in an ammonium sulphate/ammonium hydroxide buffer equal to 0.02 mol l(-1) was chosen.

Determination of subnanomolar concentrations of cobalt by adsorptive stripping voltammetry at a bismuth film electrode.

Procedures for trace cobalt determinations by adsorptive stripping voltammetry at in situ and ex situ plated bismuth film electrodes are presented. These exploit the enhancement of the cobalt peak obtained by using the Co(II)-dimethylglyoxime-cetyltrimethylammonium bromide-piperazine-N,N'-bis(2-ethanesulfonic acid) system. The calibration graph for an accumulation time of 120 s was linear from 2 x 10(-10) to 2 x 10(-8) mol L(-1).

Adsorptive stripping voltammetric determination of cobalt in the presence of dimethylglyoxime and cetyltrimethylammonium bromide.

A sensitive procedure for determination of micro-traces of Co(II) by adsorptive stripping voltammetry is proposed. The procedure exploits the enhancement of the cobalt peak obtained by use of the system Co(II)-dimethylglyoxime-piperazine-1,4-bis(2-ethanesulfonic acid)-cetyltrimethylammonium bromide. Using the optimized conditions, a detection limit (based on the 3 sigma criterion) for Co(II) of 1.

Modification of catalytic adsorptive stripping voltammetric method of hexavalent chromium determination in the presence of DTPA and nitrate.

The voltammetric procedure for determination of traces of Cr(VI) [ Anal. Chim. Acta (1992) 262:103] was modified by changing the temperature of the measurements.