Stripping Voltammetric Procedure Research Articles

A Convenient Strategy for the Voltammetric Direct Determination of Ce(III) in Environmental Waters Using a Multi-Walled Carbon Nanotubes Modified Screen-Printed Carbon Electrode.

A simple and fast stripping voltammetric procedure for trace determination of Ce(III) in environmental water samples has been developed. The procedure of cerium determination in the presence of Alizarin S and acetate buffer was employed as the initial method. The adsorption material, multi-walled carbon nanotubes, was used as a screen-printed electrode modifier ensuring efficient accumulation of the Ce(III)-Alizarin S complex. The calibration graph for Ce(III) for an accumulation time of 60 s was linear in the range from 1 × 10-8 to 7 × 10-7 mol L-1 with the linear correlation coefficient r = 0.997. The detection limit was estimated from three times the standard deviation of low Ce(III) concentration and an accumulation time of 60 s was about 3.5 × 10-9 mol L-1. The proposed method was successfully applied to Ce(III) determination at trace levels in environmental water samples, such as river, lake and rain water with recoveries ranged from 93% to 98%.

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 very good proportionality between the Tl(I) peak current and its concentration was evidenced in the range from 5 × 10-10 up to 5 × 10-7 mol L-1 (R = 0.9989) for 120 s of deposition and from 2 × 10-10 up to 2 × 10-7 mol L-1 (R = 0.9988) for 180 s. A limit of detection (LOD) of 8 × 10-11 mol L-1 for a deposition time of 180 s was calculated. The effects of interfering ions on the Tl(I) analytical signal were studied. The proposed method was applied for quantitative Tl(I) detection in water certified reference material TM 25.5 as well as in spiked real water samples, for which satisfactory recovery values between 98.7 and 101.8% were determined.

Activated Screen-Printed Boron-Doped Diamond Electrode for Rapid and Highly Sensitive Determination of Curcumin in Food Products.

Due to a great interest in the beneficial properties of polyphenolic antioxidant curcumin (CCM), sensitive and accurate methods for determining CCM are needed. The purpose of our research was to develop a very simple, fast, and sensitive differential pulse adsorptive stripping voltammetric (DPAdSV) procedure using an electrochemically activated screen-printed boron-doped diamond electrode (aSPBDDE) for the determination of CCM. The activation of the SPBDDE was accomplished in a solution of 0.1 mol/L NaOH by performing five cyclic voltammetric scans in the range of 0-2 V, at ν of 100 mV/s. The changes in surface morphology and the reduction of the charge transfer resistance due to the activation of the electrode resulted in the amplification of the CCM analytical signal on the aSPBDDE. As a result, an extremely sensitive measurement tool was formed, which under optimized conditions (0.025 mol/L PBS of pH = 2.6, Eacc of 0.3 V, tacc of 90 s, ΔEA of 100 mV, ν of 150 mV/s, and tm of 10 ms) allowed us to obtain a limit of detection (LOD) of 5.0 × 10-13 mol/L. The aSPBDDE has proven to be a highly effective tool for the direct determination of CCM in food samples with high accuracy and precision. The results are in agreement with those obtained using ultra-high-performance liquid chromatography coupled with mass spectrometry and electrospray ionization (UHPLC-ESI/MS).

(Invited) Electrochemistry of Exceptionally Inert Systems: Determination and Speciation of Arsenic(III) and Arsenic(V)

There has been growing interest in development of new methods for the determination of arsenic oxo species due to their high toxity and increasing population in the environment. Electrochemical methods for the determination of arsenic can be considered as complimentary to spectroscopic and chromoatographic ones because they are fairly simple, and they are subject to different selectivity criteria. In this respect, various stripping voltammetric procedures are becoming popular. The actual stripping voltammetric measurement consists of two steps in which preconcentration of an analyte at the electrode surface is followed by the so called „stripping” step involving electrode reaction recorded in a form of the voltammetric peak. A representative approach involves reduction of the analyte anions upon application of the sufficiently negative potential to form As(0) on the electrode (e.g. gold) surface; this step is followed by voltammetric oxidation (anodic stripping) of the deposit (to As(III)). In a case of so called cathodic stripping voltammetry, the stationary Hanging Mercury Drop Electrode (HMDE) is often used. During the preconcentration step, an insoluble salt (e.g. Cu3As2) is produced on the electrode surface. There is also a need to differentiate between As(III) and As(V) oxo-species, which are relatively more and less toxic, respectively.Because sensitivity and detection limit in electroanalytical determinations strongly depend on the current densities measured, there is a need to search for specific catalytic materials that would induce otherwise highly slow and irreversible redox processes of As(III) (oxidation) and, in particular, As(V) (reduction). Our research interests concern development of highly specific catalytic systems leading to the enhancement of the electrooxidation of arsenic (III). We explore here the capability of various noble metals nanoparticles (Pt, Rh, Pd) of inducing the arsenic(III) oxidation in acidic medium. The recorded currents have been compared to those observed previously at the electrodes modified with oxocyanoruthenates, the most potent system for the electrocatalytic oxidation of AsIII(OH)3. Reduction of arsenic (V) is even the more inert reaction. Network films of bimetallic (PtRu) nanoparticles (bare and derivatized) permit preconcentration of arsenic(V) species on their surfaces. The stripping step would allow determination of low concentrations of arsenic (10-6 mol/dm-3 or lower).

Sensitive adsorptive stripping voltammetric procedure of Imatinib determination in spiked urine samples using solid lead microelectrode

AbstractThis article reports for the first time the application of solid lead microelectrode for organic compound determination. The proposed sensor was used for anticancer drug Imatinib quantification by adsorptive stripping voltammetry. Procedure of Imatinib determination was developed utilizing advantages ensured by solid lead microelectrode: reusability and durability for a long period of time and its ecological character as compared to film electrodes. The detection limit of Imatinib determination was calculated to be 1.9 × 10−10 mol L−1. The analytical usability of the developed procedure was confirmed by acceptable recoveries of Imatinib determination in spiked urine samples.

Application of Double Deposition and Stripping Steps System for Minimization of Interferences of Peaks’ Overlapping in Anodic Stripping Voltammetry

AbstractAn anodic stripping voltammetric procedure for the determination of bismuth in the presence of excess of Cu2+ ions at two ex situ plated gold film electrodes was described. The procedure is based on utilization of two deposition and two stripping steps system. The presented procedure ensures increasing the sensitivity of Bi3+ determination and minimization of interferences related to peaks’ overlapping. The calibration graph for bismuth determination was linear from 2.5×10−9 to 2×10−8 mol L−1 for deposition time of 300 s at both working electrodes while detection limit was 7.7×10−10 mol L−1.

Application of a Solid Bismuth Microelectrode in an Adsorptive Stripping Voltammetric Procedure of Trace Tin Quantification

A novel solid bismuth microelectrode in combination with adsorptive stripping voltammetry is demonstrated as a simple and fast method for determination of tin. The proposed method includes the formation of a tin complex with cupferron in the solution and deposition on the solid bismuth microelectrode. The selection of the most optimal parameters determining the sensitivity of the elaborated procedure was made. Under optimized parameters (pH = 4.6; acetate buffer concentration: 0.1 mol l−1; cupferron concentration: 2 × 10−4 mol l−1; activation potential/time: −2.5 V/5 s; deposition potential/time: −0.6 V/40 s), a linear response of Sn(II) in the concentration range of 8 × 10−9 do 8 × 10−7 mol l−1 (r = 0.9984) was obtained with a detection limit of 2.1 × 10−9 mol l−1. The interferences of foreign ions and organic matrix of environmental water samples were carefully studied. The accuracy of the method was studied by analyzing certified reference materials SPS-WW1 Waste Water and SPS-SW1 Surface Water as well as Bystrzyca river and rain water, and passable results were obtained.

Electrochemically Activated Screen-Printed Carbon Sensor Modified with Anionic Surfactant (aSPCE/SDS) for Simultaneous Determination of Paracetamol, Diclofenac and Tramadol.

In this work, an electrochemically activated screen-printed carbon electrode modified with sodium dodecyl sulfate (aSPCE/SDS) was proposed for the simultaneous determination of paracetamol (PA), diclofenac (DF), and tramadol (TR). Changes of surface morphology and electrochemical behaviour of the electrode after the electrochemical activation with H2O2 and SDS surface modification were studied by scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The influence of various parameters on the responses of the aSPCE/SDS such as pH and concentration of the buffer, SDS concentration, and techniques parameters were investigated. Using optimised conditions (Eacc. of −0.4 V, tacc. of 120 s, ΔEA of 150 mV, ν of 250 mV s−1, and tm of 10 ms), the aSPCE/SDS showed a good linear response in the concentration ranges of 5.0 × 10−8–2.0 × 10−5 for PA, 1.0 × 10−9–2.0 × 10−7 for DF, and 1.0 × 10−8–2.0 × 10−7 and 2.0 × 10−7–2.0 × 10−6 mol L−1 for TR. The limits of detection obtained during the simultaneous determination of PA, DF, and TR are 1.49 × 10−8 mol L−1, 2.10 × 10−10 mol L−1, and 1.71 × 10−9 mol L−1, respectively. The selectivity of the aSPCE/SDS was evaluated by examination of the impact of some inorganic and organic substances that are commonly present in environmental and biological samples on the responses of PA, DF, and TR. Finally, the differential pulse adsorptive stripping voltammetric (DPAdSV) procedure using the aSPCE/SDS was successfully applied for the determination of PA, DF, and TR in river water and serum samples as well as pharmaceuticals.

A Highly Sensitive Square-wave Adsorptive Anodic Stripping Voltammetry for Trace Determination and Speciation of Palladium at Bismuth Film Modified Glassy Carbon Electrode using 1,2 Dihydroxy-cyclobut-1,2-ene 3,4 dione Schiff Base Reagent

The detection of precious metal ion moieties is of utmost significance for environmental control. Thus, the current study provides a low cost and highly-accurate square wave adsorptive anodic stripping voltammetric procedure (SW-AdASV) at a Bi film (BiF/GCE) for the analysis of the lower levels of palladium (II) ions. The proposed SW-AdASV methodology was based on the selective accumulation of the palladium (II) chelat of the newly Schiff base reagent of 1,2 dihydroxy-cyclobut-1,2-ene-3,4-dione (DCED) in a universal buffer of pH=2-3. Under the optimized analytical parameters, the plot of the palladium (II) concentration versus the corresponding anodic peak current was linear over a wide range of [5×10-9 – 2.5×10-6 molL-1 Pd] with a correlation coefficient of R2=0.9995 and excellent repeatability with RSDs of (3.3-3.8%) (n=5). In the SW-AdASV approach, the lower limits of detection (LOD) and quantitation (LOQ) as calculated were discovered to be 1.07×10-9 and 3.57×10-9 molL-1, respectively. The current sensor offered interference from several active metal ions, such as Hg2+ and Cd2+. Lastly, the developed SW-AdASV method with (BiF/GCE) was successfully applied for the detection of lower levels of Pd2+ in water. Furthermore, this procedure presents a sensitive, accurate process with short analytical time, ruggedness, robustness, and reproducibility.

Electroanalysis of diquat using a glassy carbon electrode modified with natural hydroxyapatite and β-cyclodextrin composite

The present work reports the development of a low-cost and reliable differential pulse adsorptive stripping voltammetric procedure for the detection of diquat (DQ) in water, using a glassy carbon electrode (GCE) modified with β-cyclodextrin (β-CD)/Natural hydroxyapatite (NHAPP0.5) composite material. The structural characterization of the natural hydroxyapatite and its modified counterpart was achieved using several techniques including X-ray Diffraction, Fourier Transform Infrared Spectroscopy and Thermal Analysis. By comparing the physico-chemical characteristics of hydroxyapatite material before and after reaction with β-CD, all of these techniques have demonstrated the successful grafting process of β-CD on the surface hydroxyl groups of hydroxyapatite, using citric acid (CA) as cross linker. The electrochemical features and permeability properties of the obtained materials, coated as thin film onto the GCE surface were characterized using ion exchange multisweep cyclic voltammetry. The β-cyclodextrin modified hydroxyapatite (NHAPp0.5-CA-β-CD) was evaluated as electrode modifier for DQ sensing. The electroanalytical procedure followed two steps: the chemical preconcentration of DQ under open-circuit conditions, and the differential pulse voltammetric detection of the preconcentrated pesticide. Various experimental parameters likely to influence the sensibility of electrode were fully investigated and optimized. A linear calibration curve for DQ in the concentration range of 5 × 10−8 – 4.5 × 10−7 mol L−1 was obtained at GCE/NHAPp0.5-CA-β-CD, with a detection limit of 4.66 × 10−10 mol L−1 (DL = 3S/M). The proposed method was successfully applied to the determination of DQ in spring water.

A novel catalytic adsorptive stripping voltammetric method for the determination of germanium ultratraces in the presence of chloranilic acid and the V(IV)\xb7HEDTA complex

A novel, sensitive catalytic adsorptive stripping voltammetric procedure which can be used to determine trace amounts of germanium is described. The method is based on the interfacial accumulation of the complex formed by Ge(IV) and the product of the reduction of chloranilic acid on the hanging mercury drop electrode or the renewable silver amalgam film electrode, and its subsequent reduction from the adsorbed state followed by the catalytic action of the V(IV)·HEDTA complex. The presence of V(IV)·HEDTA greatly enhances the adsorptive stripping response of Ge. The reduction of the Ge(IV) in the presence of chloranilic acid and V(IV)·HEDTA was investigated in detail and the effects of pH, electrolyte composition, and instrumental parameters were studied. Under optimal conditions, the catalytic peak current of germanium exhibited good linearity for Ge(IV) concentrations in the range of 0.75–60 nM (for 60 s of accumulation at −0.1 V, r2 = 0.995) and a low limit of detection (LOD = 0.085 nM). The procedure was successfully applied to determine Ge in water samples.

Simultaneous Analysis of Paracetamol and Diclofenac Using MWCNTs-COOH Modified Screen-Printed Carbon Electrode and Pulsed Potential Accumulation.

A differential-pulse adsorptive stripping voltammetric (DPAdSV) procedure with the use of pulsed potential accumulation and carboxyl functionalized multiwalled carbon nanotubes modified screen-printed carbon electrode (SPCE/MWCNTs-COOH) was delineated for simultaneous analysis of paracetamol (PA) and diclofenac (DF). The use of carboxyl functionalized MWCNTs and pulsed potential accumulation improves the analytical signals of PA and DF, and minimizes interferences from surfactants. After optimization of analytical conditions for this sensor, the peak currents of the two compounds were found to increase linearly with the increase in their concentration (5.0 × 10−9–5.0 × 10−6 mol L−1 with a detection limit of 1.4 × 10−9 mol L−1 for PA, and 1.0 × 10−10–2.0 × 10−8 mol L−1 with a detection limit of 3.0 × 10−11 mol L−1 for DF). For the first time, the electrochemical sensor allows simultaneous determination of PA and DF at concentrations of 24.3 ± 0.5 nmol L−1 and 3.7 ± 0.7 nmol L−1, respectively, in wastewater samples purified in a sewage treatment plant.

First Electrochemical Sensor (Screen-Printed Carbon Electrode Modified with Carboxyl Functionalized Multiwalled Carbon Nanotubes) for Ultratrace Determination of Diclofenac.

A simple, sensitive and time-saving differential-pulse adsorptive stripping voltammetric (DPAdSV) procedure using a screen-printed carbon electrode modified with carboxyl functionalized multiwalled carbon nanotubes (SPCE/MWCNTs-COOH) for the determination of diclofenac (DF) is presented. The sensor was characterized using optical profilometry, SEM, and cyclic voltammetry (CV). The use of carboxyl functionalized MWCNTs as a SPCE modifier improved the electron transfer process and the active surface area of sensor. Under optimum conditions, very sensitive results were obtained with a linear range of 0.1–10.0 nmol L−1 and a limit of detection value of 0.028 nmol L−1. The SPCE/MWCNTs-COOH also exhibited satisfactory repeatability, reproducibility, and selectivity towards potential interferences. Moreover, for the first time, the electrochemical sensor allows determining the real concentrations of DF in environmental water samples without sample pretreatment steps.

Sensitive Determination of Folic Acid using a Solid Bismuth Microelectrode by Adsorptive Stripping Voltammetry

AbstractAn adsorptive stripping voltammetric procedure of folic acid determination with the use of a new voltammetric sensor with a prolonged application‐solid bismuth microelectrode was described. The proposed microelectrode is characterized by more eco‐friendly properties as compared to in situ formed bismuth film electrodes due to the fact that bismuth ions are not needed as a component of supporting electrolyte for metal film plating. Furthermore the above mentioned fact simplifies and shortens a measurements procedure. Parameters affected folic acid determination were studied. After a procedure optimization the calibration graph was found to be linear in the range: 5×10−10 to 1×10−8 mol L−1 (accumulation time: 120 s). The obtained detection limit of folic acid determination for accumulation time of 120 s was 1.8×10−10 mol L−1. Possible interferences deriving from a presence of other organic and surface active compounds were studied. The analysis of pharmaceutical preparation was positively performed following the presented procedure.

Extremely sensitive germanium stripping voltammetric determination with the use of a new Ge(IV)-catechol-V(IV)-HEDTA catalytic adsorptive system

It was found that the addition of V(IV)-EDTA or V(IV)-HEDTA to a solution containing the Ge(IV)-catechol complex induced certain catalytic processes that significantly enhanced the adsorptive stripping voltammetric (AdSV) response of germanium. The catalytic enhancement achieved with V(IV)-HEDTA was determined to be 7.4 times higher than that in the presence of V(IV)-EDTA; the former oxidant was therefore selected for the development of a new, sensitive catalytic adsorptive stripping voltammetric (CAdSV) procedure of germanium quantification. The optimal CAdSV Ge(IV) response was obtained in a 0.05 M acetate buffer with a pH of 4.4, in the presence of 1.0⋅10−3 M of catechol, 1.0⋅10−3 M of V(IV) and 1.5⋅10−3 M of HEDTA. The sensitivity of the new method was 25.2 nA/nM and the catalytic response was linear within the range of 5·10−11 M to 2·10−8 M Ge(IV) for 80 s of accumulation. The limit of detection was found to be 1.0·10−11 M. The reproducibility was equal to 3.0%. Interferences from inorganic ions and surface-active substances were evaluated. The procedure was applied to determine Ge(IV) in mineral water. It was also shown that both the hanging mercury drop electrode and the non-toxic renewable silver amalgam film electrode can be applied for Ge(IV) quantification by means of the elaborated method, with similar performance.

Simple, insensitive to environmental matrix interferences method of trace cadmium determination in natural water samples

A simple, fast, and inexpensive anodic stripping voltammetric procedure for trace determination of cadmium in natural water samples containing high concentrations of surface-active substances was described. It was proved that interferences from the organic matrix such as surface-active substances could be removed by the addition of Amberlite XAD-7 resin to the analyzed sample prior to the voltammetric measurement. A renewable mercury film silver-based electrode (Hg(Ag)FE) was used as the working electrode. The following optimum conditions were found: 0.1 mol L−1 acetic acid, accumulation potential of − 0.8 V, and accumulation time of 30 s. The linear range of Cd(II) was observed over the concentration range from 5 × 10−8 mol L−1 to 6 × 10−5 mol L−1, with a correlation coefficient equal to 0.997. The detection limit of Cd(II) for preconcentration time of 30 s was 1.3 × 10−8 mol L−1. The proposed procedure was successfully tested for the detection of cadmium in different non-pretreated and non-deaerated real water samples.

Extractive stripping voltammetry at carbon paste electrodes for determination of biologically active organic compounds

In this review, procedures based on extraction accumulation into carbon pastes as main principle of voltammetric determination of biologically active organic compounds are summarized for the first time. This combination is commonly presented as rapid, effective, and advantageous alternative to standard analytical methods based on chromatographic and spectrometric principles. However, to date, a comprehensive review focusing exclusively on different applications of extractive stripping voltammetry has not been reported yet. Herein, the main attention is paid to the principles of extraction-based methods, and all the important factors, working conditions, and parameters influencing more or less the respective analytical performance, including the task of often extraordinary selectivity and good detection capabilities. Various properties as sensitivity, experimental arrangement, scope of application, and theoretical background are also assessed and critically commented. As a point of special importance, medium-exchange procedures are surveyed and shown as effective tools offering a very high selectivity and well applicable in clinical and pharmaceutical analysis. It is assumed that presented information can contribute to a wider applicability of extractive stripping voltammetry, helping in the development of other methods based on these still nonconventional stripping voltammetric procedures. This review also contains a systematic part, in which various methods and approaches of this kind that have already been published, concerning various biologically active organic compounds, such as alkaloids, terpenoids, amino acids, hormones, fat-soluble vitamins, food additives, pesticides, and pharmaceuticals.

A rapid and sensitive voltammetric determination of sulphur in biodiesel in samples no treated and treated with TMAH

The control of environmental pollution has demanded increasingly determination of sulphur in a variety of matrices. Different analytical methods have been developed for the determination of this analyte in biodiesel fuel using various analytical techniques, including spectroanalytic and chromatographic methods. In this work a square-wave cathodic adsorptive stripping voltammetric (SW-AdCSV) procedure is proposed for the determination of sulphur in biodiesel, using a glassy carbon electrode modified with mercury-film (MFE). A buffer solution containing sodium acetate 1.4molL−1 and acetic acid 2% was used as supporting electrolyte in two different media (methanol an propanol). The voltammetric measurements were performed adding 70μL of biodiesel sample previously treated with tetramethylammonium hydroxide (TMAH) to the supporting electrolyte. The method showed good linearity (r=0.998) in the determination of sulphur in biodiesel (medium-concentration of 2.68×10−8molL−1 (1.07×10−3mgkg−1) for a confidential level of 95%. Low values of limit of detection-LOD (3.29×10−10molL−1 (1.32×10−5mgkg−1) and limit of quantification-LOQ (1.10×10−9molL−1 (4.40×10−5mgkg−1) indicate a good sensitivity of the method. A validation of the procedure was carried out by comparing this procedure with the results obtained by an official method, using the same sample, through Teste-t of Student (confidence level of 95%). These results indicated that both methods are statistically equivalent, thus demonstrating the feasibility of the new method.

Hybrid Catalytic Materials for Determination and Speciation of Electrochemically Inert Analytes: Arsenic(III) and Arsenic(V)

There has been growing interest in development of new methods for the determination of arsenic due to its high toxity and increasing population in the environment. Electrochemical methods for the determination of arsenic can be considered as complimentary to spectroscopic and chromoatographic ones because they are fairly simple and they are subject to different selectivity criteria. In this respect, various stripping voltammetric procedures are becoming popular. The actual stripping voltammetric measurement consists of two steps in which preconcentration of an analyte at the electrode surface is followed by the so called „stripping” step involving electrode reaction recorded in a form of the voltammetric peak. A representative approach involves reduction of the analyte anions upon application of the sufficiently negative potential to form As(0) on the electrode (e.g. gold) surface; this step is followed by voltammetric oxidation (anodic stripping) of the deposit (to As(III)). In a case of so called cathodic stripping voltammetry, the stationary Hanging Mercury Drop Electrode (HMDE) is often used. During the preconcentration step, an insoluble salt (e.g. Cu3As2) is produced on the electrode surface. Because sensitivity and detection limit in electroanalytical determinations strongly depend on the current densities measured, there is a need to search for specific catalytic materials that would induce otherwise highly slow and irreversible redox processes of As(III) (oxidation) and, in particular, As(V) (reduction). Our research interests concern development of highly specific catalytic systems leading to the enhancement of the electrooxidation of arsenic (III). We explore here the capability of various noble metals nanoparticles (Pt, Rh, Pd) of inducing the arsenic(III) oxidation in acidic medium. The recorded currents have been compared to those observed previously at the electrodes modified with oxocyanoruthenates, the most potent system for the electrocatalytic oxidation of AsIII(OH)3. Reduction of arsenic (V) is even the more inert reaction. Network films of bimetallic (PtRu) nanoparticles (bare and derivatized) permit preconcentration of arsenic(V) species on their surfaces. The stripping step would allow determination of low concentrations of arsenic (10-6 mol/dm-3 or lower).

Development simple and sensitive voltammetric procedure for ultra-trace determination of U(VI)

A simple and sensitive adsorptive stripping voltammetric procedure for the determination of trace concentration of U(VI) in natural water samples was developed. In order to remove surface active compounds from water sample solutions, a TiO2/Al2O3 photocatalysis system was applied. The linear calibration graph of U(VI) in the simultaneous presence of 2mgL−1 anionic, cationic and nonionic surfactants, in the range from 5×10−10 to 2×10−8molL−1 (180s) was achieved. The detection limit obtained in the solution after the use of UV-irradiation (10min) with TiO2/Al2O3 photocatalyst (0.9g) is equal to 2.3×10−10mol L−1. The presented procedure was successfully applied to uranium determination in SLEW-3 certified reference material, and to river water samples. In addition, a very low detection limit (2.9×10–11molL−1) for accumulation time of 180s was achieved due to application of a reversible deposited mediator (Zn) in the step of lead film electrode preparation.