Bismuth Film Electrode Research Articles

Novel Insights into the Distribution of Reduced Sulfur Species in Prairie Pothole Wetland Pore Waters Provided by Bismuth Film Electrodes

Mercury/gold amalgam and bismuth film electrodes (BiFEs) were used to make the first centimeter-scale measurements of redox species in benthic pore waters of prairie pothole wetlands across a hydrologic gradient. Sulfide in pore waters increased across this system from negligible sulfide in hydrologically up-gradient recharge wetlands to thousands of micromolar in down-gradient discharge wetlands. Field measurements of sulfides using the BiFE were tested against an established colorimetric assay. Sulfide measured with the BiFE agreed well with colorimetric measurements but is not subject to analytical artifacts associated with methods needed to extract the pore waters. Use of Hg/Au and BiFE electrodes should allow for rapid in situ detection of redox active species, especially sulfide concentrations of >500 μM, in pore waters over seasonal to decadal time scales. Such measurements are needed to understand important biogeochemical and environmental processes such as carbon cycling and contaminant attenuati...

Environmentally-friendly in situ plated bismuth-film electrode for the quantification of the endocrine disruptor parathion in skimmed milk

An in situ bismuth-film electrode (BiFE) together with square-wave cathodic voltammetry (SWCV) was used to determine the concentration of the endocrine disruptor parathion in skimmed milk. The experimental conditions (deposition time, deposition potential and Bi (III) concentration) were optimized for the preparation of the BiFE. A glassy carbon electrode was used as the substrate. The selection of the chemical composition of the supporting electrolyte and the solution pH was aimed at improving the reduction of parathion at the BiFE surface. In addition, the parameters of the square-wave cathodic voltammetry were adjusted to improve the sensor performance. A cathodic current identified at −0.523V increased linearly with the parathion concentration in the range of 0.2–2.0μmolL−1 (R=0.999). The sensitivity of the calibration curve obtained was 4.09μALμmol−1, and the limits of detection (LOD) and quantification (LOQ) were 55.7nmolL−1 and 169.0 nmolL−1, respectively. The performance of the sensor was tested using a sample of skimmed milk with parathion added. The same determination was carried out by UV–vis spectroscopy and the results obtained were used for the statistical evaluation of the data obtained.

Simultaneous determination of lead and tin at the bismuth film electrode by square wave stripping voltammetry and chemometric methods

Square wave stripping voltammetry for the simultaneous determination of lead and tin by using radial basis function artificial neural networks was conducted.

Adsorptive stripping voltammetry of In(iii) in the presence of cupferron using an in situ plated bismuth film electrode

A sensitive and selective method for the determination of trace concentration of indium in natural water samples using adsorptive stripping voltammetry at an in situ plated bismuth film electrode was described.

Bismuth film electrode for anodic stripping voltammetric measurement of silver nanoparticle dissolution

A straightforward protocol for measuring low concentration levels of Ag(I) using bismuth film electrode (BiFE) in combination with anodic stripping voltammetry was developed and studied as a suitable alternative to current methods for detecting the dissolution of silver nanoparticles (Ag NPs). The BiFE was prepared in-situ on the surface of a supporting glassy carbon electrode. Several key operational parameters were examined and optimized, e.g. accumulation potential, accumulation time and concentration of Bi(III). The BiFE revealed good linear operation in the examined concentration range of 10–90μgL−1 Ag(I) with r2 of 0.998, calculated limit of detection (3σ) of 2.1μgL−1 obtained after 60s accumulation, and favorable repeatability with RSD of 3.6% (50μgL−1, n=10). The method was successfully tested through measuring Ag(I) in the supernatant of a commercial Ag NP suspension and the performance was superior to the potentiometric measurement using silver ion-selective electrode.

A simple and easy way to enhance sensitivity of Sn(IV) on bismuth film electrodes with the use of a mediator

For the first time an in situ-plated bismuth film electrode prepared with the use of a reversibly deposited mediator (Zn) was applied to anodic stripping voltammetry of the metal ions. This simple and easy way of the electrode surface modification by metal films was suggested to increase the voltammetric signal of Sn(IV) and, consequently, to improve the sensitivity and tin detection limit. The structural and chemical information about the bismuth films plated with and without the use of the mediator were derived from AFM and XPS data analysis.

A pencil-lead bismuth film electrode and chemometric tools for simultaneous determination of heavy metals in propolis samples

A simultaneous determination of Zn, Cd, Pb and Cu in raw propolis samples, employing square wave anodic stripping voltammetry and chemometric tools, was developed. For this purpose, a pencil-lead bismuth film electrode was used as a working electrode. In order to optimize the parameters of square wave voltammetry a Box–Behnken design combined with desirability function was used. Different algorithms such Asymmetric Least Squares (AsLS) and Correlation Optimized Warping (COW) were employed in order to preprocess the raw data. Partial Least Squares (PLS) and Artificial Neuron Networks (ANN) were used to predict the concentration of the four metals in the samples. The method was tested successfully on raw propolis samples obtained from different localities of the Province of Buenos Aires, Argentina and the results were validated with recovery assays.

Differential Pulse Anodic Stripping Voltammetry Detection of Cadmium with Nafion-Graphene Modified Bismuth Film Electrode

Differential Pulse Anodic Stripping Voltammetry Detection of Cadmium with Nafion-Graphene Modified Bismuth Film Electrode

Preparation of dendritic bismuth film electrodes and their application for detection of trace Pb (II) and Cd (II)

In this paper, dendritic Bi film electrodes with porous structure had successfully been prepared on glassy carbon electrode using a constant current electrolysis method based on hydrogen bubble dynamic templates. The electrode prepared using a large applied current density showed an increased internal electroactive area and a significantly improved electrochemical performance. The analytical utility of the prepared dendritic Bi film electrodes for the determination of Pb (II) and Cd (II) in the range of 5–50μg·L−1 were presented in combination with square wave stripping voltammetry in model solution. Compared with non-porous Bi film electrode, the dendritic Bi film electrode exhibited higher sensitivity and lower detection limit. The prepared Bi film electrode with dendritic structure was also successfully applied to real water sample analysis.

Determination of trace amounts of Ga(III) by adsorptive stripping voltammetry with in situ plated bismuth film electrode

The determination of trace gallium using adsorptive stripping voltammetry at an in situ plated bismuth film electrode was described. The method was based on simultaneous film formation and the Ga(III)–cupferron complex preconcentration at −0.65V and its cathodic stripping during the potential scan. The effect of Bi(III) and cupferron concentration, the influence of deposition potential and time, and the scan rate on the determination of Ga(III) were studied. A linear response in the concentration range of 3×10−10 to 3×10−7molL−1 (r=0.998) was obtained with detection limit of 1.05×10−10molL−1 using accumulation time of 180s. Finally, the bismuth film electrode was successfully applied for the determination of Ga(III) in certified reference material seawater NASS-5 with satisfactory results.

Sequential Voltammetric Determination of Uranium, Cadmium and Lead by Using the ex situ Bismuth Film Electrode: Application to Phosphate Fertilizers

AbstractA sequential voltammetric procedure for the determination of uranium, cadmium and lead was investigated at an ex situ bismuth film electrode (BiFE). First, the adsorptive stripping voltammetry was applied to assay the U(VI)‐cupferron complex in the differential pulse mode (detection limit of 1.0 µg L−1, 200 s accumulation time). Through the manipulation of the same aliquot of the sample, efforts were made to quantify cadmium and lead by square wave anodic stripping voltammetry. Detection limits of 2.03 µg L−1 for Cd (II) and 2.43 µg L−1 for Pb (II) were calculated (100 s accumulation time). The methodology was successfully applied to phosphate fertilizer samples after open vessel wet decomposition (HNO3/H2O2). The following value ranges were evaluated: U (VI) 37.2–150 mg kg−1, Pb (II) 78.3–204 mg kg−1 and Cd (II) 44.1–71.6 mg kg−1. Validation was performed by using the standard reference materials SRM‐695 – phosphate fertilizer – and SRM‐1643e – water.

Determination of the Free Metal Ion Concentration Using AGNES Implemented with Environmentally Friendly Bismuth Film Electrodes.

Ex situ plated Bi film electrodes (Bi-FE) have been employed, for the first time, to measure the free concentration of Pb(II) in aqueous solutions using absence of gradients and Nernstian equilibrium stripping (AGNES) with stripping chronopotentiometry (SCP) quantification. The amount of deposited Pb°, below a certain threshold, follows a Nernstian relationship with the applied potential. This threshold can be interpreted as the frontier of transition from surface deposition to solid (bulk) formation of Pb°. AGNES with Bi-FE yielded a very good detection limit (3σ) for Pb(II) of 6.0 × 10(-9) M with an applied gain of 398 and a deposition time of 400 s. The ability of the Bi film electrode to perform speciation measurements was demonstrated for Pb(II)-PSS and Pb(II)-IDA systems. The measured values with the Bi-FE were in good agreement with the values obtained using the Hg film electrode and/or the values reported in the literature.

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.

Combining Alkaline Extraction and in Situ Plated Bismuth Film for Reliable Quantification of Zn in Multivitamin Formulations

AbstractIn this work a bismuth film electrode (BiFE) plated in situ onto glassy carbon was used to quantify Zn2+ in multivitamin formulation samples by square wave anodic stripping voltammetry. For partially water‐soluble multivitamin tablets, an alkaline extraction with 1.0 mol L−1 NaOH aqueous solution was adopted. This procedure was simple, fast and efficient to extracting Zn from sample matrix. Moreover, this procedure was able to make the method less susceptible to interferences from Cu2+, since it remains at extracting vessel as insoluble Cu(OH)2. For fully water‐soluble effervescent tablets, sample pretreatment was not required.

In situ bismuth-film electrode for square-wave cathodic voltammetric detection of pendimethalin at nanomolar level

An in situ plated bismuth-film electrode (BiFE) was used for the study of the herbicide pendimethalin. A single peak was observed by cyclic voltammetry at −0.520V associated with the reduction of pendimethalin in HCl solution at pH3.0. Square-wave cathodic voltammetry (SWCV) was used for the analytical procedures after the preparation of the BiFE using 10.0μmolL−1 Bi(III) for 80s at −0.250V. A peak current at −0.585V related to the reduction of the herbicide was obtained, which increased linearly with the pendimethalin concentration in the range of 0.3 to 1.0μmolL−1. The limit of detection attained was 37.0nmolL−1. The sensor prepared in situ was applied for the determination of pendimethalin in simulated samples of tap water and sea water with satisfactory results being obtained compared with the UV–vis spectroscopy technique. In addition, pendimethalin was spiked and determined at nanomolar level in samples of water collected from a local river. The recovery values for such experiments were between 93% and 96%.

Electrochemical deposition of bismuth on activated graphene-nafion composite for anodic stripping voltammetric determination of trace heavy metals

In this study, we report the first example of a bismuth film electrode plated in situ using activated graphene (AG). The AG was prepared through of process of chemical activation of graphene oxide (GO) with KOH to create pores. The composite electrode was enhanced as an electrochemical sensing platform to determine trace Zn2+, Cd2+, and Pb2+ using differential pulse anodic stripping voltammetry. The surface morphology of the AG-NA/Bi composite film modified electrode was investigated by scanning electron microscopy and transmission electron microscopy. The electrochemical properties of the AG-NA/Bi composite electrode were evaluated to examine the effects of experimental variables, such as deposition potential, deposition time, bismuth concentration, and stirring speed during pre-concentration, on the determination of trace metals in 0.1M acetate buffer solution (pH 4.5). Linear calibration curves ranged from 5 to 100μgL−1 for trace heavy metal ions. The detection limits were 0.57μgL−1 for Zn2+, 0.07μgL−1 for Cd2+, and 0.05μgL−1 for Pb2+ (S/N=3). The limits of detection achieved are much lower than the guideline for drinking water quality provided by the World Health Organization (WHO). The AG-NA/Bi composite film electrodes were successfully applied to analysis trace metals in real samples.

Voltammetric Behavior of Testosterone on Bismuth Film Electrode: Highly Sensitive Determination in Pharmaceuticals and Human Urine by Square‐Wave Adsorptive Stripping Voltammetry

AbstractIn this paper, an electrochemical application of bismuth‐film electrode (BiFE) fabricated via ex‐situ electrodeposition onto a glassy carbon electrode for testosterone determination was investigated in aqueous and aqueous/surfactant solutions. In cyclic voltammetry, the compound showed one irreversible and adsorption‐controlled reduction peak. The BiFE revealed good linear response in the examined concentration range of 1 to 45 nmol L−1 testosterone in BrittonRobinson buffer, pH 5.0 containing 3 mmol L−1 cetyltrimethylammonium bromide. The limit of detection was 0.3 nmol L−1 (0.09 ng mL−1). Finally, the BiFE was satisfactorily applied for quantitation of testosterone in both pharmaceutical (oil‐based ampoule) and biological (human urine) samples.

Determination of Se(iv) as a 5-nitropiazselenol complex by adsorptive stripping voltammetry at an in situ plated bismuth film electrode

In this paper a simple, selective, sensitive and reproducible stripping method based on adsorption of Se(iv) in the form of a 5-nitropiazoselenol complex at the surface of anin situplated bismuth film electrode was introduced.

Operation of bismuth film electrode in more acidic medium

A new approach for application of bismuth film electrode (BiFE) under more acidic conditions is presented. The BiFE was prepared in-situ on a glassy carbon substrate electrode and employed for anodic stripping voltammetric measurement of Zn(II) in 0.01molL−1 hydrochloric acid (pH 2.0) in the presence of dissolved oxygen. The addition of potassium sodium tartrate tetrahydrate into the measurement solution resulted in significant improvement of the electroanalytical performance of BiFE via inhibition of hydrogen evolution. The BiFE revealed an excellent linear response towards Zn(II) in the examined concentration range of 10 to 100μgL−1 with the calculated LoD of 1.3μgL−1 associated with 300s accumulation step and satisfactory repeatability of 4.8% (RSD). A preliminary study of simultaneous detection of selected trace metal ions, i.e. Pb(II) and Cd(II), together with Zn(II) was also carried out. Finally, the applicability of the proposed method was corroborated via measuring Zn(II) in a real tap water sample.

Electrochemical sensor based on bismuth-film electrode for voltammetric studies on vitamin B2 (riboflavin)

Riboflavin (or vitamin B2) was successfully studied by voltammetric techniques and determined in oral, syrup and tablet samples using an ex situ plated bismuth-film electrode (BiFE). Cyclic voltammetry demonstrated that in acetate buffer (pH 4.0) vitamin B2 undergoes an adsorption-controlled quasi-reversible electron transfer reaction. The peak potentials observed were pH-dependent, involving the same numbers of protons and electrons. The calibration curve provided by square-wave adsorptive stripping voltammetry (SWAdSV) exhibited two slopes: the first ranged from 0.3 to 0.8μmolL−1 vitamin B2 and the second from 1.0 to 9.0μmolL−1. In the case of the first slope, the detection limit was 100nmolL−1 and the quantification limit was 300nmolL−1. Also, for the measurements, excellent selectivity, repeatability and stability were attained. Fluorescence was employed as the comparative technique and the outstanding performance of the BiFE-SWAdSV for riboflavin determination was verified.