Preconcentration Time Research Articles

Electrosensing tool for nonsteroidal drug flufenamic acid at multiwalled carbon nanotubes modified graphite electrode

The sensitivity, high aspect ratio, electrocatalytic and enhancing properties of multi-walled carbon nanotubes (MWCNTs) were well utilized to fabricate the present sensor based on graphite electrode. The modified sensor used to determine flufenamic acid (FFA), a non-steroidal anti-inflammatory drug. The sensitivityand selectivity of sensor towards FFA, were enriched at MWCNTs modified electrode compared to the bare one. The influence of pH, amount of modifier, preconcentration time, sweep rate and concentration on the signal enhancement of FFA were studied. FFA is electrochemically active in all the pHs studied, but in pH 4.2 an accentuated peak was observed. From the acquired data, mixed adsorption diffusioncontrolled process and two protons, two electrons involvement was witnessed. The currents obtained from square wave voltammetric (SWV) measurements were linearly associated with FFA concentration. The concentration of FFA was found linear in the concentration range of about 0.1 µM to 0.8 µMwith alimit of detection (LOD) value of 2.2 nM. Contrasted with prior reports, the present result is very impressive on account of modifiers utilized and expedient because of its affectability, selectivity,and LOD value. In addition, the modified electrode processes some unique characteristics, such as appropriate charge transfer rate, enduring stability, exceptional reproducibility and antifouling effects. The practical usefulness of the modified sensor was evaluated by the analysis of FFA in spiked human urine samples.

Integrated optical and electrochemical detection of Cu2+ ions in water using a sandwich amino acid-gold nanoparticle-based nano-biosensor consisting of a transparent-conductive platform.

In this paper, an optical-electrochemical nano-biosensor was introduced for measuring Cu2+ ion concentrations in water. A multi-step procedure was used to fabricate the transparent-conductive biosensor platform consisting of an l-cysteine–gold nanoparticle-based sandwich structure. First, colloidal gold nanoparticles (GNPs) were synthesized according to the Turkevich–Frens method with some modifications and then functionalized with l-cysteine molecules (GNP/l-cys). Then, cyclic voltammetry was preformed in buffered solutions containing HAuCl4·3H2O for gold nanoparticle electrodeposition on cleaned ITO glasses. The GNP-electrodeposited ITO glasses (ITO/GNPs) were thermally treated in air atmosphere for 1 hour at a temperature of 300 °C. Following the procedure, the gold nanoparticles on ITO/GNPs substrates were functionalized with l-cysteine to prepare ITO/GNPs/l-cys substrates. Finally, the sandwich-type substrates of ITO/GNPs/l-cys⋯Cu2+⋯l-cys/GNPs were fabricated by accumulation of Cu2+ ions using an open circuit technique performed in copper ion buffer solutions in the presence of previously produced colloidal GNP/l-cys nanoparticles. The effective parameters including GNP/l-cys solution volume, pre-concentration pH and pre-concentration time on the LSPR and SWV responses were investigated and optimized. The fabricated transparent-conductive platforms were successfully assessed as a nano-biosensor for detection of copper ions using two different methods of square wave voltammetry (SWV) and localized surface plasmon resonance (LSPR). As a result, the proposed biosensor showed a high sensitivity, selectivity and a wide detectable concentration range to copper ions. The total linear range and the limit of detection (LOD) of the nano-biosensor were 10–100 000 nM (0.6–6354.6 ppb) and below 5 nM (0.3 ppb), respectively. The results demonstrated the potential of combining two different optical and electrochemical methods for quantitation of the single analyte on the same biosensor platform and obtaining richer data. Also, these results indicated that the developed LSPR-SWV biosensor was superior to many other copper biosensors presented in the literature in terms of linear range and LOD. The developed nano-biosensor was successfully applied in the determination of trace Cu2+ concentration in actual tap water samples.

Versatile Sensor Modified with Gold Nanoparticles Carbon Paste Electrode for Anodic Stripping Determination of Brexpiprazole: A Voltammetric Study

A variety of voltammetric methods have been carried out for determination of brexpiprazole (BRX) using cyclic voltammetry (CV) and two different type anodic stripping methods; differential pulse (AS-DP) and square wave (AS-SWV) at modified carbon paste electrode with gold nanoparticles (AuNPs-CPEs). Additionally, electrochemical impedance spectroscopy (EIS) technique has been utilized for characterization of the different electrodes. Electrochemical oxidation behavior of BRX shows an irreversible anodic peak at 0.88 V versus Ag/AgCl, in Britton–Robinson buffer (BR) at pH 4.0, 50s preconcentration time and −0.5 deposition potential. Rectilinear relationship between the peak current versus concentration was obtained over the ranges of 1.32 × 10−6–6.45 × 10−6 and 1.32 × 10−7– 6.45 × 10−7 mol L−1 for AS-DP and AS-SWV respectively. The lowest concentration that can be detected for both for AS-DP and AS-SWV was 3.99 × 10−7 and 3.32 × 10−8 mol L−1 respectively; the utilized methods have been devoted adequately for the estimation of BRX in its pure and dosage form.

Sensors based on ruthenium-doped TiO2 nanoparticles loaded into multi-walled carbon nanotubes for the detection of flufenamic acid and mefenamic acid

Recent advances to utilize two or more nanoparticles for developing novel sensors with superior sensitivity have spurred advanced detection limits even at low concentrations. In this research, a blend of rutheniumdoped TiO2 (Ru-TiO2) nanoparticles and multiwalled carbon nanotubes (MWCNTs) loaded into carbon paste matrix to fabricate a novel Ru-TiO2/MWCNTs-CPE sensor was used for the detection and quantification of flufenamic acid (FFA) and mefenamic acid (MFA) drugs. The surface morphology of Ru-TiO2 was assessed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). Sensitivity and selectivity of the electrode was improved at the Ru-TiO2/MWCNTs modified CPE compared to nascent CPE due to the amazing surface distinctive characteristics of the modifier at pH 5.0. The effect of concentration of the modifier, pH, pre-concentration time, sweep rate and concentration on signal enhancement of FFA and MFA was studied. The square wave voltammetry (SWV) currents are linearly related in the concentration range of 0.01 μM–0.9 μM with the detection limit values of 0.68 nM for FFA and 0.45 nM for MFA, respectively. The developed electrode assembly was used for the quantification of both the drug analytes in human urine samples.

Low-cost screen-printed sensors on-demand: Instantly prepared sparked gold nanoparticles from eutectic Au/Si alloy for the determination of arsenic at the sub-ppb level

We report on the straightforward preparation of gold nanoparticles (AuNPs) through a direct metal-to-substrate electric discharge at ambient conditions at 1.2 kV between the source metal (gold) and low-cost graphite screen-printed electrodes (SPEs). Considering that sparked nanoparticles are generated on the basis of an evaporation-condensation process, comparative experiments by using Au and a eutectic Au/Si (97/3 wt%) alloy were conducted. The so-modified sparked AuNP-SPE and eAuNP-SPE, respectively, were characterized by scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). Data revealed a 2.4-fold electro active surface of AuNPs in the case of eAuNP-SPE. Compared with the unmodified SPEs, sparked electrodes exhibited two distinct electrode-electrolyte interfaces, characterized by different time-constants. EIS data were successfully modeled to an equivalent electric circuit that considers sparked-induced morphological features of the sensing surface and concomitant alterations of the diffusion process. Both types of sparked electrodes endowed sensitivity to otherwise inactive plain SPEs to the anodic stripping voltammetric detection of arsenic. Compared with AuNP-SPE, eAuNP-SPE exhibited ca. 5-fold sensitivity and offered fast (30 s preconcentration time) measurements, linear response over the concentration range from 0.5 to 12 ppb and a limit of detection (3σ/m criterion) of 0.22 ppb. Moreover, eAuNP-SPEs were successfully applied to the determination of arsenic in drinking water. Results demonstrated a new type of AuNP-modified low cost electrodes lend themselves to extremely simple preparation while offering enhanced detection capabilities and a wide-scope of applicability.

FIA-coupled spectrophotometric method for determination of Cr (VI) traces in natural waters: application of in-line dissolution of 1,5-diphenylcarbazide after heat treatment and activated alumina as adsorbent for preconcentration.

This work proposes the quantification of Cr (VI) ions in natural waters in trace level, using activated alumina (Al2O3) as preconcentration support, controlled in-line dissolution of the solidified chromophore diphenylcarbazide after heat treatment and spectrophotometric detection. The manifold ensures high sensitivity of analytical response, good repeatability, and stability. In this work, optimization of experimental conditions of a flow injection system was chosen as the parameters for greater sensitivity and better selectivity. The selected optimized conditions were 0.30molL-1 for H2SO4 concentration, system flow rate as 0.40mLmin-1, sample injection volume of 192.50μL, 2min for preconcentration time, and 0.10molL-1 for eluent concentration. The analytical curves obtained for real sample analysis show linear range from 0.192 to 0.961μM, linear correlation coefficient R = 0.9997 and LOD = 0.024μM. The preconcentration factor of about four times was obtained through the passage of 800μL of a standard solution containing 0.961μM of Cr (VI) through mini-column of preconcentration followed by elution at 192.5μL of NH4OH 0.1molL-1 solution. The solid chromogenic reagent presented high durability (weeks in daily use with mass of 0.0993g) and good reproducibility in analytical signal. The reactivation of the mini-column of alumina should be executed after ten injections of eluent, using 800μL of HCl 0.02molL-1 solution in flow through the same. Each cycle of injection and elution of the sample takes about 5min on the proposed terms. Despite the length of each cycle still be high, low concentrations can be detected using a technique of relatively low cost. This is due in part, the association dissolution of the chromogenic reagent directly in the line and the preconcentration step. Another important factor is the economy of reagent chromogenic, low generation of reject contributing to better quality of the environment, and the high potential for applications to work in field.

Synthesis of a magnetic WO3 nanocomposite for use in highly selective preconcentration of Pb(II) prior to its quantification by FAAS.

A novel sorbent consisting of WO3 and Fe3O4 is described for preconcentration of Pb(II). It was prepared without consumption of organic solvents. The nano composite was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, alternating gradient force magnetometer and Brunauer-Emmett-Teller. Having high surface area and being formed oxygen sheets propose the nanocomposite as a sorbent. Adsorption and desorption conditions were optimized and Pb(II) is quantified by flame atomic absorption spectroscopy. The sorbent can highly selectively preconcentrate Pb(II) at pH values between 3 and 7. The preconcentration time is short and sorbent is re-usable. Under the optimized conditions, the method has the following figures of merit: (a) limit of detection of 0.60ngmL-1, (b) relative standard deviation (n= 5) of 0.87%, (c) preconcentration factor of 33.33 and (d) linearity of dynamic range (10-200ng.mL-1). Isotherm adsorption, kinetic adsorption and thermodynamic adsorption were stablished. The material was applied to the preconcentration of Pb(II) from herbal medicines. Graphical abstract Schematic presentation of a nanocomposite (Fe3O4 - WO3) that was prepared from sodium tungstate (Na2WO4), oxalic acid, HCl and magnetic Fe3O4 nanoparticles for the magnetic solid phase extraction of lead at trace levels.

Simultaneous voltammetric analysis of lead, copper and mercury ions by carbon paste electrode based on 1-(3-aminopropyl) imidazole modified polymer

ABSTRACTIn this study, a carbon paste electrode modified with a novel 1-(3-aminopropyl) imidazole functionalised crosslinked chlorosulfonated poly(styrene)-divinyl benzene polymer was used for selective and sensitive determination of the trace amounts of Pb2+, Cu2+ and Hg2+ ions by square wave anodic stripping voltammetry. The effect of some parameters such as paste composition, pH, preconcentration time, reduction potential and time, type of supporting electrolyte and potential scan rate on the determination of metal ions were investigated to find the optimal conditions. The effective open-circuit accumulation of the studied metal ions was succeeded only by the modification of the carbon paste electrode with functional polymer. For 6 min open-circuit preconcentration, the detection limit of Pb2+, Cu2+ and Hg2+ was found to be 5, 9 and 14 µgL−1, respectively at 100 mVs−1. The results confirmed that the lower concentration levels of these trace metal ions can be determined with the increase of preconcentration time and/or potential scan rate. Good detection limits and large dynamic concentration ranges were also obtained for their binary and ternary mixtures. The optimised method was successively applied to determine the concentration of Pb2+, Cu2+ ions in the tap water sample and Cu2+ ion in the waste water sample in the presence of possible interfering species (RSD<1%, recoveries 96–110% for 4 min preconcentration).

On-Line Fabric Disk Sorptive Extraction via a Flow Preconcentration Platform Coupled with Atomic Absorption Spectrometry for the Determination of Essential and Toxic Elements in Biological Samples

Fabric phase sorptive extraction (FPSE) has gained notable attention and interest both in batch and automatic mode utilizing advanced sol-gel derived microextraction sorbents and the hydrophobic/hydrophilic properties of fabric substrates. Recently, the innovative on-line fabric disk sorptive extraction (FDSE) has opened new opportunities in the field of automatic sample preparation (preconcentration/separation). A novel sol-gel sorbent based on caprolactone-dimethylsiloxane-caprolactone block polymer comprised of a non-polar dimethylsiloxane and hydrophilic caprolactone as a coating on hydrophobic polyester fabric substrate and its evaluation in an automatic FDSE system coupled with flame atomic absorption spectrometry (FAAS), is presented for the first time. The capabilities of the proposed flow injection system were assessed for trace Cu(II), Ni(II), Zn(II), Pb(II), and Cd(II) determination in urine samples. The method was based on the on-line formation of target analytes with ammonium pyrrolidine dithiocarbamate (APDC) and their retention onto the surface of the fabric disk medium. Methyl isobutyl ketone (MIBK) was used to elute metal–APDC complexes directly into the nebulizer-burner system of FAAS. For 90 s of preconcentration time, enhancement factors of 250, 130, 185, and 36 and detection limits (3 s) of 0.15, 0.41, 1.62, and 0.49 μg L−1 were obtained for Cu(II), Ni(II), Pb(II), and Cd(II), respectively. For 30 s of preconcentration time, an enhancement factor of 49 and a detection limit of 0.12 μg L−1 was achieved for Zn(II) determination. The precision, expressed as relative standard deviation (RSD), was lower than 3.5% for all metals. The accuracy of the proposed method was sufficient and evaluated by analyzing certified reference materials and biological samples.

A novel sensor for the determination of Hg2+ in waters based on octadentate ligand immobilized multi-walled carbon nanotube attached to paraffin wax impregnated graphite electrodes (PIGE)

In this work, the synthesised octadentate ligand immobilised multi-walled carbon nanotubes (MWCNTs) modified electrode as an electrochemical sensor of Hg2+ is reported. The octadentate/MWCNTs composites were coated on the polished surface of paraffin impregnated graphite electrode for fabricating the enhanced electrochemical sensing platform for Hg2+ determination. The octadentate ligand contains four N and four O donor atoms which coordinate with the metal ion in stripping medium have been investigated. Surface morphology of the fabricated modified electrode was studied using scanning electron microscope (SEM). The modified electrode was characterised by electrochemical impedance spectroscopy (EIS) and square wave anodic stripping voltammetry (SWASV). Further various factors such as preconcentration time, effects of pH and different electrolytes were optimised for the detection of Hg2+. Under the optimised condition, anodic stripping voltammetry of Hg2+ showed a response in a linear range from 2.4 - 180 nM and the limit of detection was 0.8 nM for Hg2+ (S/N = 3). Interference studies with Cd2+,As3+,Cu2+, Ag+,Ni2+,Fe3+,Zn2+,Sn2+ and Pb2+ showed an insignificant effect on the electrochemical response of Hg2+. The proposed modified electrode exhibited an excellent performance with good reproducibility, selectivity and stability. The practical application of the modified electrode was also evaluated by the detection of Hg2+ in well water and lake water samples with good recovery results.

Diethylenetriamine ion-imprinted silica gel for copper determination in tap water

This paper proposes the preparation of a hybrid adsorbent material organically modified with N1-[3-(trimethoxysilyl)propyl]diethylenetriamine and imprinted ionically with Cu(II) ions. The structure of functionalized silica matrix with an organic group containing electron-donating nitrogen atoms allows several applications such as adsorption of metal ions, electrocatalytic studies, and development of electrochemical sensors. The electrochemical behavior of the hybrid material was investigated using a carbon paste electrode in different electrochemical techniques: cyclic voltammetry, differential pulse voltammetry, differential pulse anodic stripping voltammetry, and chronoamperometry. DPASV yielded the best results and linear response to Cu(II) in the concentration range of 6.0 × 10−4 to 5.4 × 10−3 mmol L−1 (R2 = 0.999; n = 9) using a pre-concentration time (tpc) of 1800 s at a reduction potential (Ered) of − 0.51 V versus SCE and a scan rate of 20 mV s−1, with a detection limit estimated at 1.82 × 10−7 mmol L−1. The samples were evaluated using the proposed sensor and a good recovery of Cu(II) was obtained in the range from 92.88 to 110.89%. The proposed method for DPASV was used for Cu(II) determination in samples of tap water, and the results from literature and that of flame atomic absorption spectrometry.

Selection of Conditions for Chromatomembrane Gas Extraction at Its Combination with the Gas-Adsorption Preconcentration of Analytes

Optimal conditions (temperature, porous structure and configuration of mass exchange layer in the chromatomembrane cell, and also the direction of water sample and extractant gas flows through it) for the chromatomembrane gas extraction of volatile organic compounds from aqueous solutions in combination with the gas-adsorption preconcentration of the analytes are selected. An analysis scheme based on a combination of these methods and a two-step thermal desorption of analytes ensures the shortening of the preconcentration time by several times compared to the schemes involving traditional bubbling. Metrological characteristics are given and the accuracy of the developed scheme of analysis is proved.

2,4,6-Trimercaptotriazine incorporated gold nanoparticle modified electrode for anodic stripping voltammetric determination of Hg(II)

This work describes a sensitive and selective method for the determination of aqueous Hg(II) by anodic stripping voltammetry at 2,4,6-Trimercaptotriazine (TMT)/gold nanoparticles (GNPs) modified electrode. The TMT/GNPs modified electrode was prepared by sequential coating of gold nanoparticles and TMT. The TMT/GNPs modified electrode was characterized by surface morphological studies, UV-Visible spectroscopy, and Electrochemical Impedance spectroscopy (EIS). Various operational parameters which influence the determination of Hg(II) such as electrolyte, pH, deposition time, and preconcentration time have been studied. TMT/GNPs modified electrode was highly sensitive towards the determination of Hg(II) and showed a linear range of 16 nM–2000 nM with a detection limit of 5.3 nM (S/N = 3). The electrode surface was regenerated on each stripping response, which was renewed by dipping the electrode in 0.2 M HNO3 for 3 min. Interference of other metal ions was also investigated and result confirms that the presence of other cations and anions did not show any interfernce. The newly developed TMT/GNPs modified electrode was successfully applied for the determination of Hg(II) in lake water samples with good recovery.

Electrochemical determination of nepafenac topically applied nonsteroidal anti-inflammatory drug using graphene nanoplatelets-carbon nanofibers modified glassy carbon electrode

Nepafenac is novel ophthalmic agents with a unique prodrug structure and superior corneal permeability to other currently available topical nonsteroidal anti-inflammatory drugs. A graphene nanoplatelets and carbon nanofibers modified glassy carbon electrode was developed and used as first electrochemical sensor for the determination of nepafenac. The effective combination of graphene and carbon nanofibers resulted in electrochemical sensor with large surface area, high sensitivity, good stability and selectivity. After method optimization, the square wave voltammograms, at a preconcentration time of 60 s, display two linear ranges of 4.0 × 10−6–1.5 × 10−5 M and 2.5 × 10−7–4.0 × 10−6 M for drug quantification with a detection limit of 6.3 × 10−8 M. The modified electrode was employed for fast assay of nepafenac in ophthalmic solution with satisfactory results and rapid run time of 66 s in comparison with previously reported analytical methods.

Voltammetric monitoring of linezolid, meropenem and theophylline in plasma

Treatment of healthcare associated Pneumonia (HCAP) caused by Methicillin-resistant Staphylococcus aureus (MRSA) requires therapeutic protocols formed of linezolid (LIN) either alone or in combination with meropenem (MERO) and theophylline (THEO). The inter-individual pharmacokinetic variations require the development of reliable therapeutic drug monitoring (TDM) tools especially in immunocompromised patients. A sensitive square wave voltammetric sensor using multiwalled carbon nanotubes (MWCNTs) modified carbon paste electrode in Britton-Robinson buffer was developed and validated. Experimental parameters such as pH, percentage of MWCNTs, and pre-concentration time were optimized. The sensor was employed at pH 11.0 for the determination of LIN in plasma within a concentration range of 2.5 × 10−8 - 8.0 × 10−6 mol L−1without interference from co-administered medications. On the other hand, simultaneous monitoring of LIN, MERO and THEO in plasma was feasible at pH 3.0 over concentration ranges of 4.0 × 10−7- 9.0 × 10−5, 8.0 × 10−7- 9.0 × 10−5 and 8.0 × 10−7 - 9.0 × 10−5 mol L−1, respectively. The performance of the proposed sensor was validated and the applicability for TDM has been demonstrated in plasma of healthy volunteers.

Preconcentration of the Herbicide Simetryn Using the ITIES System

In the present work, the preconcentration of the herbicide simetryn was carried out using the interface of two immiscible electrolyte solutions. For the electrochemical studies, the techniques of cyclic voltammetry and square wave voltammetry were used. The results showed that it is possible to preconcentrate the herbicide in one of the phases of the system. A higher peak current for the simetryn extraction was observed in the square wave voltammetry experiments at 300 seconds of preconcentration time; this is related to the concentration of extracted herbicide. Finally, with the results obtained, it is possible to develop an alternative analytical methodology for the determination or quantification of this type of analytes at lower concentrations.

Electrochemical determination of trace mercury in water sample using EDTA-CPE modified electrode

The analytical performance of the EDTA-CPE sensor that is designed for the detection of metals was studied. EDTA plays an important role in the complexation of metal ions because of their good and high response to these ions. The modified electrode EDTA-CPE was used for the voltammetric determination of mercury ions (square wave voltammetry). Sodium chloride solution 0.3mol−1 was used as the support electrolyte. Using optimal parameters, calibration graph is linear (varying from 5 to 35∗10−4mol/l) for 5min of pre-concentration time with the detection limit of 16, 6×10−9molL−1. These results indicate that the developed method is simple, with high stability and sensitivity for the determination of low concentration of Hg (II).

Polyurethane foam functionalized with phenylfluorone for online preconcentration and determination of copper and cadmium in water samples by flame atomic absorption spectrometry

In this work, a polyurethane foam (PUF) functionalized with phenylfluorone (PUF-PF) was packed in a minicolumn and used as an on-line preconcentration system for cadmium and copper determination in water samples. The experimental conditions (both chemical and physical) were optimized to achieve the highest sensitivity. A study of possible ion interference on the retention of cadmium and copper was also performed. The enrichment factors obtained were 14 and 16 for copper and cadmium, respectively, using a preconcentration time of 1min. The proposed system allowed the determination of metals with limits of detection (3σ) of 0.8 and 0.3μgL−1 for Cu(II) and Cd(II), respectively. The precision of the procedures was also calculated as 7.6% for Cu(II) (at 25μgL−1) and 4.0% for Cd(II) (at 10μgL−1). The limits of quantification obtained were 2.6 and 0.8μgL−1 for Cu(II) and Cd(II), respectively. Cadmium and copper contents in water samples (from rivers and swimming pools) were determined by applying the proposed procedure. In these samples, recovery tests were conducted in order to evaluate the accuracy of the method; the recovery percentages varied between 83 and 109%.

High Sensitive Voltammetric Determination of Betamethasone on an Amalgam Film Electrode

A voltammetric method for fast and high sensitive determination of betamethasone (BM) using an amalgam film silver based electrode (Hg(Ag)FE) was developed. Cyclic voltammetry study revealed that the BM reduction process is diffusion controlled with the participation of two electrons and two protons. In the optimum conditions, calibration curve was linear for BM in the concentration range from 5·10−9 mol L−1 (1.96·10−6 g L−1) to 0.8·10−6 mol L−1 (3.14·10−4 g L−1), with a detection limit of 1.6·10−9 mol L−1 for preconcentration time of 45 s. Repeatability of method was determined as RSD % for betamethasone concentration of 0.1·10−7 mol L−1 as 2.1% (n = 5). The proposed method was successfully applied and validated by studying the recovery of betamethasone in commercially available drugs.

Design and Development of a Renewable Galinstan Silver Based Film Electrode for Stripping Voltammetry

The fabrication of the renewable galinstan silver based film electrode (G(Ag)FE) and its application for voltammetric determination of lead, bismuth and thallium ions in acetate buffer solution are presented. One drop of galinstan is placed in the sensor body, which had been filled with the saturated solution of sodium sulfite. The procedure of mechanical refreshing the galinstan film involves pulling the silver wire inside, through the galinstan chamber, and then pushing it back outside the sensor body. It provides very good surface reproducibility and it enables Pb2+, Bi3+ and Tl+ determination in the micromolar concentration levels using short preconcentration times.