Voltammetric Determination of Iron(III) in Water

Un electrodo serografiado y un electrodo de grafito pirolítico de borde plano sin modificar fueron utilizados en una voltamperometría de onda cuadrada para determinar cantidades traza de Fe(III) en muestras reales de agua de botella mineral.

A square wave voltammetric procedure for the detn. of trace amts. of Fe(III) was developed at an unmodified edge plane pyrolytic graphite (EPPG) electrode and a screen printed electrode (SPE).  This simple procedure was applied to real samples of com. bottled mineral water.  Sensitive results in the micromolar region could be achieved without modification of the electrode.  Using the WHO guideline limits for the Fe(III) concn. in drinking water, recovery percentages at an EPPG gave 103 % and 107 %, and 98.6 % and 95.0 % at a SPE for the 5.36 μM (0.3 mg L^-1) and 53.6 μM (3.0 mg L^-1) addns. of Fe(III), resp.

• Lu, Min; Compton, Richard G.
• Electroanalysis, Ahead of Print

Square wave voltammetric determination of methiocarb insecticide based on multiwall carbon nanotube paste electrode

• Mediante una voltamperometría de onda cuadrada con electrodo de pasta de carbono de estructura de nanotubos se ha estudiado la determinación del insecticida metiocarb en suelos y ríos.

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• Cyclic voltammogram of methiocarb in 0.1 M H₂SO₄ exhibited an irreversible anodic peak at about +1285 mV vs. Ag/AgCl.  Electrooxidn. and detn. of methiocarb in spiked soil, river water, and agrochem. formulation were realized on a newly prepd. carbon-nanotube paste electrode by applying square wave voltammetry (SWV).  The dE _p/dpH value indicated that the oxidn. mechanism involved the coupling of H⁺ with the oxidn. process.  The peak signals were linearly related to methiocarb concn. in the range of 1.5-59.1 mg L^-1 with a detection limit of 0.45 mg L^-1.  The accuracy and selectivity of the proposed method were shown by calcg. the recoveries of methiocarb from soil, river water, and pesticide formulation Mesurol.  The calcd. percent recoveries for soil and river water samples spiked with 30.0 μg g^-1 and 40.0 μg mL^-1 levels were 99.3 ±1.2 and 98.5 ±0.3 at 95% confidence limit, resp.
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• Inam, Recai; Bilgin, Cansu
• Journal of Applied Electrochemistry (2013), 43(4), 425-432

Simultaneous Voltammetric Determination of Captopril and Hydrochlorothiazide on a Graphene/Ferrocene Composite Carbon Paste Electrode

El captopril y la hidroclorotiazida han sido determinadas simultáneamente a través de una voltamperometría de pulso diferencial con un electrodo de pasta de carbono compuesto de grafeno y ferroceno. Los dichos compuestos fueron hallados en muestras farmacéuticas y clínicas. 

In this work, a voltammetric method has been developed for the simultaneous detn. of captopril (CPT) and hydrochlorothiazide (HCT) in pharmaceutical combinations and clin. samples using a graphene/ferrocene composite carbon paste (GR/Fc/CP) electrode.  The electrochem. behaviors of CPT and HCT were individually and simultaneously investigated at the surface of the GR/Fc/CP electrode.  In differential pulse voltammetric (DPV) mode and under optimized exptl. conditions, CPT and HCT gave linear responses over the concn. ranges 1.0-430 μM and 0.5-390 μM (r²>0.99), resp.  The prepd. electrode could be used for simultaneous detn. of CPT and HCT in some real samples.

• Gholivand, Mohammad Bagher; Khodadadian, Mehdi
• From Electroanalysis, Ahead of Print

Voltammetric determination of isoniazid using cyclic renewable mercury film silver based electrode

Un método voltamperométrico catódico basado en un electrodo de plata con película de mercurio cíclica renovable fue investigado para la determinación de isoniazida.

A new cathodic voltammetry method for the detn. of isoniazid based on the cyclic renewable mercury film silver based electrode (Hg (Ag) FE) is presented.  The effects of various factors such as: preconcn. potential and time, pulse height, step potential and supporting electrolyte compn. are optimized.  The calibration graph is linear from 5 nM up to 500 nM (68.55 μgL^-1).  For Hg (Ag) FE with a surface area of 9.7 mm² without time consuming preconcn. the limits of detection LOD and quantification LOQ were 4.1 nM and 10.5 nM of isoniazid, resp.  The repeatability of the method at a concn. level of the analyte as low as 0.5 nM, expressed as RSD is 3.6% (n = 6).  The proposed method was successfully applied in anal. of isoniazid in simple and composed pharmaceutical formulations.

• Szlosarczyk, Marek; Piech, Robert; Bator, Beata Paczosa; Maslanka, Anna; Opoka, Wlodzimierz; Krzek, Jan
• Pharmaceutica Analytica Acta (2012), 3(9), 1000189/1-1000189/5.

Simultaneous differential pulse voltammetric determination of dopamine and uric acid with polycalconcarboxylic acid modified glassy carbon electrode

En este artículo la voltamperometría de pulso diferencial tiene la particularidad de ser utilizada con un electrodo vítreo de carbono modificado con ácido policarconcarboxílico. Los resultados obtenidos son buenos para la determinación simultánea de ácido úrico y dopamina.

• The modified electrode (PCCA/GCE) was prepd. by electrochem. polymn. of calconcarboxylic acid (CCA) on the surface of glassy carbon electrode (GCE).  The electrochem. property of the PCCA/GCE was studied by cyclic voltammetry and AC impedance method.  It was found that in a PBS of pH 6.0, the oxidn. peaks of dopamine (DA) and uric acid (UA) were completely sepd., and the p.d. of the oxidn. peaks attained to a value of 0.14 V.  Based on these findings, a selective method for simultaneous detn. of DA and UA by differential pulse voltammetry was proposed.  Linear relationships between values of oxidn. peak current and concn. of DA and UA were obtained in the ranges of 5.0-43.8 μmol·L^-1 and 5.0-50.0 μmol·L^-1, with their detection limits of 0.2 μmol·L^-1 and 0.5 μmol·L^-1, resp.  The proposed method has been used in simultaneous detn. of DA and UA in DA injections, giving values of RSD's (n = 5) of 2.43% for DA and 2.35% for UA.
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• Huang, Wen-hua; Hou, Bao-qin; Zhang, Lei
• Lihua Jianyan, Huaxue Fence (2012), 48(6), 638-642.

Use of phosphate activated glassy carbon electrode in voltammetric determination of epinephrine

• En este artículo la protagonista es la voltamperometría cíclica, que permite determinar cantidades traza de epinefrina mediante la utilización de un electrodo vítreo de carbono activado con fosfato. 

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• Phosphate activated GCE was prepd. by cyclic voltammetry, and the electrochem. behavior of epinephrine (EP) at this electrode in a phosphate buffer medium of pH 6.0 was studied.  A cyclic voltammetric method for detn. of trace amt. of EP was proposed, by which the interference of ascorbic acid to the detn. of EP was effectively eliminated.  A sensitive oxidn. peak of EP at 0.26 V (vs. SCE) was obsd.  Linear relationship between values of oxidn. peak current (i_pa) and concn. of EP was obtained in the range of 1.0 × 10^-6-1.2 × 10^-5 mol·L^-1, with detection limit (3S/N) of 3.0 × 10^-7 mol·L^-1.  This method was applied to the detn. of EP in injections, giving results in consistency with the labeled values.  Av. recovery of the method found by std. addn. method was 99.7%.
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•  Li, Jin-jin; Wang, Xue-liang; Guo, Xian-hou; Yu, Zhang-yu
• Lihua Jianyan, Huaxue Fence (2012), 48(7), 766-769

Voltammetric determination of trace elements in infusions of medicinal plants

• Para la determinación de elementos traza de importancia biológica (Cu, Zn, Cd, Pb) en hierbas de infusiones se estedió una voltamperometría de pulso diferencial de redisolución aniónica. El método de extracción llevado a cabo fue una combustión en atmósfera de oxígeno asistida por microondas.

• This work deals with the detn. of biol. important trace elements, such as copper, zinc, cadmium, and lead, in herbal infusions.  Black elder flowers (Sambuci flos), birch leaves (Betulae folium), linden flowers (Tiliae flos), peppermint (Menthae herba) and sage (Salviae herba) were used as plant material for the infusion prepns.  The method of differential pulse anodic stripping voltammetry was developed and applied for the detn. of the above mentioned trace elements in digests of plant materials as well as in herbal infusions.  The method of choice for digest prepn. was the microwave assisted combustion in an oxygen atm.  Parameters of voltammetric measurements were optimized.  The concns. of particular trace elements found in the digests; 36.6-226 μg.g^-1 for zinc, 3.78-6.96μg.g^-1 for copper, 1.59-0.39μg.g^-1 for lead and 0.208-0.106μg.g^-1 for cadmium were compared with concns. found in infusions: 32.7-1.86μg.g^-1 for zinc, 1.26-0.417μg.g^-1 for copper, 0.088-0.049μg.g^-1 for lead, and 0.076-0.021 μg.g^-1 for cadmium.  The ratios of the amts. for particular trace element transferred from plants into infusions ranged from 4% to 18%.
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• Sucman, E.; Matzke, F.
• Folia Veterinaria (2012), 56(3), 16-20

Novel nanostructured electrochemical sensor for voltammetric determination of N-acetylcysteine in the presence of high concentrations of tryptophan

La voltamperometría de onda cuadrada utilizada como un novedoso sensor electroquímico de nanoestructura (electrodo de pasta de carbono químicamente modificado con nanotubos de multiparedes), ha resultado útil en la determinación de N-acetilcisteína en muestras de orina y drogas.

• A carbon paste electrode chem. modified with multiwall nanotubes and ethynylferrocene (ETFc) was used as a selective and sensitive electrochem. sensor for the detn. of minor amts. of N-acetylcysteine (N-AC) in the presence of a high concn. of tryptophan (Trp).  Square wave voltammetry (SWV) of N-AC at the modified electrode exhibited linear dynamic range with a detection limit (3 s) of 0.08 μmol L^-1.  The sepns. of anodic peak potentials of N-AC and Trp reached 400 mV using SWV.  With good selectivity and sensitivity, the present method provides a simple method for selective detection of N-AC in real samples such as drug and urine.
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• Fouladgar, Masoud; Karimi-Maleh, Hassan; Hosseinzadeh, Rahman
• Ionics (2013), 19(4), 665-672.

Carbon paste electrode prepared from chemically modified multiwall carbon nanotubes for the voltammetric determination of isoprenaline in pharmaceutical and urine samples

La voltamperometría con electrodo de pasta de carbón con nanotubos de carbono de multiparedes modificados químicamente (con N-(3,4-dihydroxyphenethyl)-3,5-dinitrobenzamide) ha vuelto a ser estudiada para el análisis de un compuesto en cantidades traza. En este artículo se determina isoprenalina en muestras de orina y farmacéuticas

A carbon paste electrode with added multiwall carbon nanotubes chem. modified with N-(3,4-dihydroxyphenethyl)-3,5-dinitrobenzamide was used as the electrochem. sensor for the detn. of trace amts. of isoprenaline.  The modified electrode showed good electrocatalytic activity for the anodic oxidn. of isoprenaline, which was due to a substantial decrease in the anodic overpotential.  Under the optimum conditions, measurements using square wave voltammetry had a linear range in the range of 0.3 to 125.0 μmol/L of isoprenaline and a detection limit of 0.1 μmol/L.  The diffusion coeff. and kinetic parameters were detd. using electrochem. methods.  The relative std. deviation for seven successive assays of 1.0 and 20.0 μmol/L isoprenaline were 1.9% and 2.4%, resp.  This electrochem. sensor was successfully applied for the detn. of isoprenaline in human urine and injection soln. samples.

• Ensafi, Ali A.; Bahrami, Hajar; Karimi-maleh, Hassan; Mallakpour, Shadpour
• Cuihua Xuebao (2012), 33(12), 1919-1926

A simple method for voltammetric determination of trace amounts of selenium in diverse matrices

La determinación de cantidades traza de Se en aguas industriasles y en tabletas de vitaminas es posible mediante un método muy simple de voltamperometría basado en el diferencial de impulsos de reducción polarográfica de Se (IV).

"A simple and convenient method is described for the determination of low concentration selenium in samples of industrial waste and vitamin tablet. The method is based on the differential pulse polarographic reduction of Se (IV) in presence of alanine in ammonium chloride medium. Linearity of the calibration curve was achieved upto 44ppm with a limit of determination of 5 μg/L. Major metal ions copper, lead and zinc did not interfere."

• Kherwa, V.; Dubey, S.
• From Research Journal of Recent Sciences (2013), 2(ISC-2012), 51-54

Electrochemical Behavior and Voltammetric Determination of Diclofenac at a Multi-Walled Carbon Nanotube-Ionic Liquid Composite Modified Carbon Ceramic Electrode

La determinación de diclofenaco se realiza por voltamperometría, mediante la superficie de un electrodo carboncerámico modificado con nanotubos de carbono de multipared y una composición líquida iónica.

This work describes the electrochem. behavior of diclofenac on the surface of a carbonceramic electrode (CCE) modified with multi-walled carbon nanotubes (MWCNT) and an ionic liq. (IL) composite.  The MWCNT-IL composite showed an enhancement effect in the electro-oxidn. of diclofenac with respect to a bare carbon ceramic electrode.  Based on the exptl. outcomes, a possible mechanism for the electro-oxidn. of diclofenac is proposed and discussed.  Under the optimized exptl. conditions, the MWCNT-ILCCE showed a linear response to diclofenac over the concn. range 50 nM-20 μM with a detection limit of 27 nM.  The developed diclofenac sensor showed good stability, sensitivity, and reproducibility in the measurement of diclofenac in human blood plasma samples.

• Razmi, Habib; Sarhang-Zadeh, Kianoush; Mohammad-Rezaei, Rahim
• Analytical Letters, Ahead of Print

Anodic stripping voltammetric analysis of lead, cadmium and copper in the Jordan river, Utah

El plomo ha sido, una vez más, determinado mediante voltamperometría. En este estudio, además de plomo, se determina cadmio y cobre en el río Jordan (Utah) mediante voltamperometría de redisolución anódica.

This project is an ongoing multifaceted investigation of the Jordan River.  The study's intent is to monitor and asses the overall condition of the river from Utah Lake to the Great Salt Lake.  Samples of river and pond water, typical vegetation such as cattails, and some soils have been collected with ref. to sites along the river that may serve as sites for the introduction of waste and other contaminants.  These samples have so far been examd. with respect to temp. and dissolved oxygen at the sampling point.  Two river samples, one pond sample, and plant sample have been analyzed by ICP-MS for 20 different metals.  The levels of Lead, Cadmium, and Copper have been detd. by anodic stripping voltammetry at the ppb level in a variety of other water samples from the river.  The results of these measurements are disused and presented Geospatially.

Iles, Peter; Thurman, Chris; Warren, Joseph; Sanders, Wesley; Richards, Sydney; Parker, Lauren; Valcarce, Ron; Giddings, Luther; Alvarez, Mary; Bastian, Neil Abstracts of Papers, 243rd ACS National Meeting & Exposition, San Diego, CA, United States, March 25-29, 2012 (2012), ANYL-53

Voltammetric determination of carbidopa using a modified multiwall carbon nanotube paste electrode

Esta vez la voltamperometría se utiliza para determinar carbidopa, con la particularidad de que se usa un electrodo de pasta de nanotubos de carbono modificado. El estudio se lleva a cabo con voltamperometría cíclica y con voltamperometría de onda cuadrada.

A modified carbon nanotubes paste electrode (MCNTPE) was used for the sensitive voltammetric detn. of carbidopa (CD) in buffer soln. using cyclic voltammetry (CV), square wave voltammetry (SWV) and chronoamperometry (CHA).  The diffusion coeff. (D = 2.62 × 10-5 cm2 s-1) and the kinetic parameter such as the electron transfer coeff. (α = 0.37) of CD oxidn. at the surface of MCNTPE was detd. using electrochem. approaches.  It has been found that under an optimum condition (pH 9.0), the oxidn. of CD at the surface of the modified electrode occurs at a potential about 100 mV less pos. than that of an unmodified carbon nanotubes paste electrode.  SWV of CD at the modified electrode exhibited linear dynamic range with a detection limit (3σ) of 0.4μM.  Finally, this modified electrode was also examd. for the detn. of CD in urine samples.

Mohadesi, Alireza

International Journal of Electrochemical Science (2012), 7(3), 2430-2439

Differential pulse voltammetric analysis of lead in vegetables using a surface amino-functionalized exfoliated graphite nanoplatelet chemically modified electrode

En este artículo un tipo de voltamperometría de pulso diferencial fue utilizada para determinar plomo(II) en vegetales como el repollo. Para este análisis se usa un electrodo modificado químicamente con una superficie amino funcional exfoliada de grafito nanoplatelet.

A surface amino-functionalized (CONH2) exfoliated graphite nanoplatelet (xGnP) bismuth-modified electrode (CONH2xGnP/glassy carbon electrode GCE) for the detn. of lead was developed and characterized.  The hybrid material was characterized by Fourier transform IR spectroscopy (FTIR) and SEM (SEM).  The electrochem. properties of the CONH2xGnP bismuth-modified electrode were characterized by a phys. deposition method, depositing the film on a graphite electrode.  The differential pulse response was linear over the Pb(II) concn. range of 0.005-0.045 μg L-1, with a limit of detection of 0.001 μg L-1, and the linear regression equation was y = 3.75x + 0.73.  In vegetable juice (cabbage), the current increased linearly relative to the Pb(II) concns. over the concn. range 0.005-0.035 μg L-1 with the corresponding linear regression equations: y = 13.06x + 0.46, R2 = 0.9970.

 Ion, Ion; Ion, Alina Catrinel                                                      

 Sensors and Actuators, B: Chemical (2012), 166-167, 842-847.  

A comparative study on carbon paste electrodes modified with hybrid mesoporous materials for voltammetric analysis of lead (II)

En el siguiente artículo se estudia el análisis voltamperométrico del plomo (II) mediante electrodos de pasta de carbono modificados con materiales híbridos mesoporosos. Se tratra de un voltamperometría de redisolución-adsorción.



We have chem. functionalized four types of ordered mesoporous silicas (referred to as MPS1-MPS4) with 5-mercapto-1-methyltetrazole (MTTZ), and have incorporated these materials into carbon paste electrodes (CPEs) to obtain sensors for the detn. of Pb(II) ion in aq. media by adsorptive stripping voltammetry.  Materials and MPS1-MPS4, were characterized by nitrogen adsorption-desorption measurements, X-ray diffraction, transmission electron microscopy, SEM and elemental anal.  The effect of the mesostructure of the MPS on the performance of the sensors was evaluated with respect to linear ranges, sensitivities, selectivities, precision and limits of detection.  The CPE modified with MPS1 (a silica with mesopores of 37 Å in diam. and pseudo-spherical particle morphol.) exhibited the best inter-electrode reproducibility and sensitivity, a linear range between 1 and 30 ppb and a limit of detection of 0.8 ppb.  The CPE modified with MPS4 (a silica with hexagonal mesopores of 58 Å in diam., cylindrical particle morphol. and bigger size) exhibited the poorest inter-electrode reproducibility and sensitivity, a linear range between 5 and 100 ppb, and a limit of detection of 2.6 ppb.  The differences in the voltammetric responses to Pb(II) therefore appear to result from differences in the coating of the inner surface with MTTZ, the pore diam., and the particle morphol. as well as the size of the hybrid MPS.  As consequence of its highest inter-electrode reproducibility and sensitivity, good linear range and low limit of detection, MPS1 can be selected as the better material to prep. modified CPE for Pb(II) detn. in aq. media by adsorptive stripping voltammetry.

Sanchez, Alfredo; Morante-Zarcero, Sonia; Perez-Quintanilla, Damian; del Hierro, Isabel; Sierra, Isabel Journal of Electroanalytical Chemistry (2013), 689, 76-82