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Showing papers on "Polarography published in 2007"


Journal ArticleDOI
TL;DR: In this paper, the behavior of folic acid at plain carbon paste electrode and electrode modified with calixarenes has been studied and shown to be rectilinear with concentration by differential pulse voltammetry.

101 citations


Journal ArticleDOI
TL;DR: In this article, the electrochemical behavior of riboflavin at a carbon paste electrode and electrodes modified with aza crown ethers have been studied using voltammetric techniques.
Abstract: The electrochemical behavior of riboflavin at a carbon paste electrode and electrodes modified with aza crown ethers have been studied using voltammetric techniques. The macrocycles used as modifiers were 1,4,8,11-tetraazacyclooctadecane; 7,16-dibenzyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane; 1,4,7,10-tetraoxa-13-azacyclopentadecane and 1,4,7,10-tetratosyl-1,4,7,10-tetraazacyclooctadecane, out of which 1,4,8,11-tetraazacyclooctadecane showed better response for riboflavin. The interaction of riboflavin with 1,4,8,11-tetraazacyclooctadecane was confirmed by complexation study in 20% DMSO + water (log K 5.58) using differential pulse polarography. The kinetic parameters viz. electron transfer coefficient and rate constant of electron transfer across the modified electrode were found to be 0.708 and 5.5 s −1 , respectively. The surface coverage of the 1,4,8,11-tetraazacyclooctadecane modified electrode was calculated to be 5 × 10 −10 mol cm −2 by cyclic voltammetry and chronocoulometry. A linear working range of 0.5 ng cm −3 to 70 μg cm −3 with a detection limit of 0.2 ng cm −3 has been obtained using 1,4,8,11-tetraazacyclooctadecane modified electrode by square wave anodic stripping voltammetry. It was possible to determine riboflavin in presence of some organic molecules like thiamine hydrochloride, nicotinamide, pyridoxine hydrochloride, ascorbic acid, para -aminobenzoic acid and l -tryptophan. Also simultaneous and quantitative determinations were achieved for combination of some of these. The electrode could be used for estimation of riboflavin in pharmaceutical and food samples.

49 citations


Journal ArticleDOI
TL;DR: In this article, the authors used dc-polarography, differential-pulse polarography, cyclic voltammetry, linear sweep and square-wave adsorptive stripping voltammetric, respectively, for determination of bulk flavoxate hydrochloride and in the pharmaceutical formulation Genurin® S.F.
Abstract: Flavoxate hydrochloride, 2-piperidinoethyl 3-methyl-4-oxo-2-phenyl-4-H-chromene-8-carboxylate, is a smooth muscle antispasmodic. Its electrochemical behavior was studied at the mercury electrode in buffered solutions containing 30% (v/v) methanol using dc-polarography, differential-pulse polarography, cyclic voltammetry, and linear sweep-and square-wave adsorptive stripping voltammetry. Sensitive and precise procedures were developed for determination of bulk flavoxate hydrochloride and in the pharmaceutical formulation Genurin® S.F, without sample pretreatment or extraction. Limits of quantitation (LOQ) of 1 × 10−5, 5 × 10−6, 1 × 10−8 and 1 × 10−9 M flavoxate hydrochloride were achieved by dc-polarography, differential-pulse polarography, linear sweep and square-wave adsorptive stripping voltammetric, respectively.

18 citations


Journal ArticleDOI
TL;DR: In this paper, a differential pulse polarographic method was developed for analysis of nicotine in various pharmaceutical formulations (chewing gum, tablets (drops) and patches), which requires a simple liquid-liquid extraction procedure for chewing gum and patches.
Abstract: A fast and simple differential pulse polarographic method was developed for analysis of nicotine in various pharmaceutical formulations (chewing gum, tablets (drops) and patches). This method requires a simple liquid-liquid extraction procedure for chewing gum and patches, or a direct dilution in supporting electrolyte for tablets before polarographic analysis. The polarographic analysis was done in a Britton-Robinson buffer (pH 6.2) as supporting electrolyte. The multimode electrode from Metrohm was used as working electrode (dropping mercury electrode). This method was applied to the determination of the nicotine content in chewing gum, tablets and patches by using the standard addition method. The results are in good agreement with the content declared by the manufacturer. The method is fast, simple and reliable, and it is a complementary method to the chromatographic method being used today for quantitative analysis of nicotine in pharmaceutical formulations. The limit of quantification is assumed to be far below 0.1 mg/l in the polarographic vessel. The method uses simple dilution and/or extraction procedures for sample preparation before polarographic analysis. It is also shown that it is possible to use a glassy carbon electrode with a mercury film (MTFE electrode) for the determination of nicotine in antismoking pharmaceutical products.

16 citations


Journal ArticleDOI
TL;DR: A fully validated, simple, sensitive, precise and inexpensive square-wave adsorptive cathodic stripping (SWAdCS) voltammetry procedure was described for trace quantification of bulk norethisterone and was successfully applied for the assay of norehisterone in Steronate tablets without interference from excipients.

14 citations


Journal ArticleDOI
TL;DR: In this paper, a cathodic differential pulse voltammetric determination of colchicine was validated using a glassy carbon electrode in HClO4/H3PO4 0.01 M. The proposed method was characterized according to ICH Harmonized Tripartite Guidance Q2(R1) by validation parameters (selectivity, linearity, accuracy, fidelity, limit of detection, and limit of quantification).
Abstract: A cathodic differential pulse voltammetric determination of colchicine was validated using a glassy carbon electrode in HClO4/H3PO4 0.01 M. Colchicine gives an irreversible, diffusion-controlled peak at −862 mV vs. Ag/AgCl reference electrode. The cathodic peak is strongly influenced by a more alkaline environment with a shift towards more negative potentials. Method optimization was carried out in parallel for three types of electrodes (glassy carbon, mercury film and bismuth film coated glassy carbon). The cathodic peak current is higher using film-coated electrodes, but shows poorer intra-day reproducibility and a longer analysis time due to film renewal. Thus, a bare glassy carbon electrode was used to determine colchicine in the concentration range of 2.4 − 50 μg mL−1 (R2 = 0.9998, n = 5), with a calculated detection limit of 0.80 μg mL−1. The proposed method was characterized according to ICH Harmonized Tripartite Guidance Q2(R1) by validation parameters (selectivity, linearity, accuracy, fidelity, limit of detection, limit of quantification) and it was successfully applied for the determination of colchicine from tablets, without the interference of the excipients. The method’s performances were evaluated and compared with both a known polarographic method and the official quantitative spectrophotometric determination from the Romanian Pharmacopoeia, Xth edition, respectively.

13 citations


Journal ArticleDOI
TL;DR: In this article, a novel reagent of analytical potential in polarographic and voltammetric analyses, α.2.α.butyrolactone arylhydrazones (α.
Abstract: 2‐Acetylbutyrolactone was characterized as a novel reagent of analytical potential in polarographic and voltammetric analyses. It forms α‐oxo‐γ‐butyrolactone arylhydrazones through Japp‐Klingemann coupling reaction with primary arylamines. α‐Oxo‐γ‐butyrolactone arylhydrazones possess an electro‐active site (azomethine center) that displays a cathodic activity at the mercury electrode. The protonated azomethine center of α‐oxo‐γ‐butyrolactone arylhydrazones is reduced by 2e/2H+ reaction to the hydrazo form. The differential pulse polarographic behavior of α‐oxo‐γ‐butyrolactone arylhydrazones was investigated in aqueous media ranging from pH 2 to 10.5. In aqueous acidic solution, α‐oxo‐γ‐butyrolactone arylhydrazones were shown to adsorb on a hanging mercury drop electrode and to be amenable to determination by adsorptive stripping voltammetry. Procedures for applying the polarographic and voltammetric methods to determination of sulfadiazine and sulfamethoxazole in pharmaceutical preparations have ...

13 citations


Patent
12 Jun 2007
TL;DR: In this paper, a handheld sensor device is provided for measuring an ion concentration in a solution, which includes a control amplifier configured to provide a current through the counter electrode and the working electrode so as to maintain a predetermined voltage between the working electrodes and the reference electrode.
Abstract: A handheld sensor device is provided for measuring an ion concentration in a solution. The solution is in an electrochemical cell that includes a counter electrode, a working electrode, and a reference electrode. The sensor includes a control amplifier configured to provide a current through the counter electrode and the working electrode so as to maintain a predetermined voltage between the working electrode and the reference electrode. The sensor also includes a current amplifier configured to measure the current provided through the counter electrode and the working electrode. In one embodiment, the sensor also includes a direct digital frequency synthesizer (DDFS) including a phase accumulator. The DDFS is configured to selectively generate a waveform specified by an electrochemical technique such as square wave voltammetry, cyclic voltammetry, linear sweep voltammetry, differential-pulse polarography, normal-pulse polarography, or other known electrochemical techniques. An example microelectrode array usable with the handheld sensor is also provided.

12 citations


Journal ArticleDOI
TL;DR: Two polarographic procedures and three adsorptive cathodic stripping voltammetric procedures were described and successfully applied for quantification of dantrolene sodium in its bulk form and in pharmaceutical formulation (Dantrolex tablets).
Abstract: The electroreduction of the muscle relaxant drug dantrolene sodium at the mercury electrode has been studied in the Britton–Robinson universal buffer of pH 2.5—11.5 containing 20% (v/v) methanol by means of dc-polarography, cyclic voltammetry and controlled-potential coulometry. Its reduction took place via three irreversible cathodic steps in solutions of pH ≤6, two steps in solutions of 6

10 citations


Journal ArticleDOI
28 Feb 2007-Talanta
TL;DR: Evaluation based on logbeta(CuL) versus pK(a) revealed that TES, TRIS, TAPS and AMPSO coordinated via amino and hydroxymethylgroups forming a five-membered chelate ring.

10 citations


Journal ArticleDOI
15 Oct 2007-Talanta
TL;DR: The goodness of phase sensitive ACP has been demonstrated comparing the determined complex formation constants with those obtained by reverse pulse polarography, a technique that minimizes the electrode adsorption effects on the measured currents.

Journal ArticleDOI
TL;DR: In this paper, a single sweep polarization (SWP) was used to detect hemin in NH3−NH4Cl buffer solution of pH 9.5 by using a single-sweep polarizer.
Abstract: Hemin, iron (III) protoporphyrin IX chloride, in NH3‐NH4Cl buffer solution of pH 9.5 produces an insensitive reduction wave at about −0.70 V (vs. saturated calomel reference electrode, SCE) by using single sweep polarography. Adding oxidant K2S2O8 to the solution, hemin reduction wave is catalyzed, yielding a parallel catalytic wave. The catalytic current is 20 times of hemin original reduction current. The derivative peak height is linearly proportional to the hemin concentration in the range of 7.5×10−8 to 4.5×10−6 mol/l, the detection limit is 5.0×10−8 mol/l. Serum albumin, common amino acids, and metal ions have no interference with the hemin determination. The proposed method has been applied to the determination of hemin content in oral liquid samples with satisfactory results. The parallel catalytic wave is attributed to the catalytic reduction of porphyrin ring of hemin at the dropping mercury electrode. The new method could be useful in biochemical, clinical, and pharmaceutical analysis.

Journal Article
TL;DR: Rate of oxidation of cysteine, γ-glutamylcysteines, cysteinylglycine and reduced glutathione by molecular oxygen has been studied polarographically in alkaline buffers by following the time changes in anodic and cathodic limiting currents of the SH- and SS-groups.
Abstract: Rate of oxidation of cysteine, γ-glutamylcysteine, cysteinylglycine and reduced glutathione by molecular oxygen has been studied polarographically in alkaline buffers by following the time changes in anodic and cathodic limiting currents of the SH- and SS-groups, respectively. Oxidation ofthiols proceeds considerably faster in contact with metallic mercury. Obtained results have been supported by Raman spectroscopy measurements.

Journal ArticleDOI
TL;DR: In this article, the polarographic reduction of 2-arylhydrazono-3-keto-3-,phenylpropionitriles (I a−i ) and 2-ylhexano-3,keto-,3-phenyl-propionite (II a−I ) over a wide pH range is reported and discussed.
Abstract: The polarographic reduction of 2-arylhydrazono-3-keto-3-phenylpropionitriles (I a−i ) and 2-arylhydrazono-3-ketobutyronitriles (II a−i ) over a wide pH range is reported and discussed. The mechanism of the electrode process is elucidated and confirmed via coulometric analysis, quantum chemical calculations and IR spectra of the electrolysis products. The molecular structures and molecular orbital energies were calculated and correlated with the redox potentials of these compounds

Journal ArticleDOI
TL;DR: In this paper, the optimal process of pre-treatment and activation of gold rotating disc electrode (AuRDE) before voltammetric determination of mercury is proposed, which provides better selectivity and significant increase of sensitivity of mercury determination.
Abstract: The optimal process of pre-treatment and activation of gold rotating disc electrode (AuRDE) before voltammetric determination of mercury is proposed. This treatment encompasses polishing of the electrode surface, electrochemical cycling, and activation. This procedure both increases determination sensitivity as well as improves determination reproducibility. The detection limit on the working electrode achieved using this approach amounted to 8.26·10−10 mol L−1for direct mercury determination in water solution (applying 200 s running accumulation). The procedure of the quantitative mercury isolation from complicated sample matrix was developed as well. It provides better selectivity and significant increase of sensitivity of mercury determination. In case of mercury isolation from one liter of water the detection limit is 6.23·10−11 mol L−1 (analyzing a greater sample volume the determined concentration could be lower).

Journal Article
TL;DR: In this paper, a two-electron reduction of anthraquinone at mercury electrodes was developed for determination of micro-to nanomolar concentrations of this analyte in mixed aqueous-methanol media.
Abstract: 2-Aminoanthraquinone (2-AA) is a genotoxic intermediate in the industrial synthesis of anthraquinone dyes. In this work, electroanalytical methods based on two-electron reduction of anthraquinone at mercury electrodes were developed for determination of micro-to nanomolar concentrations of this analyte in mixed aqueous-methanol media. Calibration plots obtained for differential pulse voltammetry and direct current voltammetry at a hanging mercury drop electrode exhibited a sigmoidal shape within the analyte's concentration range of (1-500) × 10 -7 mol L -1 , presumably because of strong adsorption of the analyte at the electrode surface. Linearity of the calibration plots was achieved for higher concentrations of 2-AA at a conventional dropping mercury electrode using DC tast polarography and differential pulse polarography, with limit of quantitation of 4 × 10 -6 mol L -1 in Britton-Robinson buffer (pH 6)-methanol mixture (1:1). Adsorption of 2-AA on the electrode surface enabled its determination at nanomolar concentrations (limit of quantitation 2.8 × 10 -9 mol L -1 ) using cathodic adsorptive stripping voltammetry in Britton-Robinson buffer (pH 2)-methanol mixture (99:1).

Journal Article
TL;DR: In this paper, an extremely sensitive pulse polarographic method for the determination of zinc dimethyldithiocarbamate (an agricultural fungicide) and zinc di-n-pentyldithIcaramate (a petroleum additive) has been developed based on the reaction of their dithIocaramate moiety with copper(II) perchlorate in acetonitrile medium.
Abstract: An extremely sensitive pulse polarographic method for the determination of zinc dimethyldithiocarbamate (an agricultural fungicide) and zinc di-n-pentyldithiocarbamate (a petroleum additive), has been developed based on the reaction of their dithiocarbamate moiety with copper(II) perchlorate in acetonitrile medium. Well defined diffusion-controlled peaks are observed at -140 mV and -130 mV (vs SCE) for zinc dimethyldithiocarbamate and zinc di-n-pentyldithiocarbamate respectively. The peaks shows approximately four-fold higher sensitivity than that obtained by pulse polarography of the zinc dithiocarbamate alone. A linear relationship is obtained between concentration of the zinc dithiocarbamate [added to copper(II)] and peak current. Using cyclic voltammetry, a probable mechanism for the zinc dithiocarbamate-copper(II) reaction has been proposed.

01 Jan 2007
TL;DR: In this article, aqueous media of BR buffer in pH range 2-12 was used for the determination of tetrakis(4-sulfonatophenyl) porphyrin tetrasodium salt (TPPS4).
Abstract: -tetrakis(4-sulfonatophenyl) porphyrin tetrasodium salt (TPPS4) was investigated in aqueous media of BR buffer in pH range 2-12. Modern electroanalytical methods, i.e DC tast polarography (DCTP) and differential pulse polarography (both at a dropping mercury electrode), differential pulse voltammetry, adsorptive stripping voltammetry, and cyclic voltammetry (all at a hanging mercury drop electrode) were used for this purpose. TPPS4 gives three cathodic signals for pH 2 - 12, first of them corresponding to a two electron quasireversible process. From these signals, the first two are suitable for the determination of TPPS4 using both polarographic methods with limit of determination about 2·10

Book ChapterDOI
04 Apr 2007

Journal ArticleDOI
TL;DR: Polarographic behavior of the genotoxic substance 1,1-dimethyl-3-phenyltriazene was investigated and optimum conditions were found for its determination by sampled direct current polarography and differential pulse polarography as mentioned in this paper.
Abstract: Polarographic behavior of the genotoxic substance 1,1-dimethyl-3-phenyltriazene was investigated and optimum conditions were found for its determination by sampled direct current polarography and differential pulse polarography at a static mercury drop electrode in the concentration range from 1 × 10 -4 to 1 × 10 -7 mol l -1 . It was established that for reduction of the triazene group four electrons are required resulting in the formation of amino and hydrazo compound. The resulting products were identified, and the reduction pathway was proposed.

Journal Article
TL;DR: In this paper, the dependence of transition state with applied potential between dropping mercury electrode and solution interface of [Mn-antibiotics-cephalothin] system at pH = 7.30 ± 0.01 and μ = 1.0 M NaClO 4 at 298 K.

Journal ArticleDOI
TL;DR: In this article, the interaction of acridine orange (AO) with double-stranded (ds) DNA in aqueous solution was investigated by linear sweep polarography (LSP) on a dropping mercury working electrode (DME).
Abstract: The interaction of acridine orange (AO) with double-stranded (ds) DNA in aqueous solution was investigated by linear sweep polarography (LSP) on a dropping mercury working electrode (DME). In pH 2.5 Britton-Robinson (B-R) buffer solution, AO had a sensitive linear sweep polarographic reductive peak at -0.89 V (vs. SCE), which could be greatly inhibited by the addition of dsDNA, with a positive shift of the peak potential. Based on the decrease of the reductive peak current, a new quantitative electrochemical determination method for dsDNA was developed with a linear range of 2.0−20.0 mg l -1 and the linear regression equation: ∆Ip" (nA) = 111.90 C (mg l -1 )+125.32 (n = 9, γ = 0.997). The influences of com- monly co-existing substances, such as metal ions, amino acid, etc., on the determi- nation were also investigated. The method is sensitive, rapid and simple with good selectivity. The new proposed method was further applied to the detection of RNA and three synthetic samples containing dsDNA with satisfactory results. The bin- ding number and the equilibrium constant between dsDNA and AO were calculated by an electrochemical method.

Journal ArticleDOI
TL;DR: In this article, a pre-monolayer of a slightly soluble metal hydroxo complexes on electrode surface facilitates the electrooxidation of aromatic aldehydes, together with establishment of equilibria between the aldehyde and a geminal diol anion.
Abstract: Formation of a pre‐monolayer of a slightly soluble metal hydroxo complexes on electrode surface facilitates the electrooxidation. This factor, together with establishment of equilibria between the aldehyde and a geminal diol anion (which is the electroactive form) play important roles in electrooxidation of aromatic aldehydes. Better understanding of chemical and electrochemical processes involved, enables application of electroanalytical methods for investigation of reactions of orthophthalaldehyde—an important analytical reagent—in alkaline solution.

Journal ArticleDOI
TL;DR: In this article, the electrochemical behavior of 1-ethyl-4-nitro-3-cyanopyrazole (1) in acidic aqueous-alcoholic solutions resembles the behavior of nitrobenzene.
Abstract: Polarography and preparative electrolysis are used to show that the electrochemical behavior of 1-ethyl-4-nitro-3-cyanopyrazole (1) in acidic aqueous-alcoholic solutions resembles the behavior of nitrobenzene. By varying the parameters of the electroreduction (ER) of compound 1, one can obtain either 1-ethyl-4-amino-3-cyanopyrazole (2) or 1-ethyl-4-amino-3-cyano-5-chloropyrazole (3). Compound 2 is formed during the ER of compound 1 in the presence of a mediator (titanium(III)) at temperatures below 10°C. Compound 3 is produced by the direct reduction of compound 1 on a lead electrode (30% ethanol, 10% HCl). The yield of amine chlorohydrates 2 and 3 is 56 and 92%, respectively. The mediated ER of compound 1 at catholite temperatures higher than 10°C yields a mixture of compounds 2 and 3; the proportion of the latter increases with temperature to become the major product at 60°C. Compound 3 is formed due to the rearrangement of the hydroxylamine derivative produced by the ER of compound 1, followed by the substitution of chlorine for the hydroxy group.

Journal ArticleDOI
TL;DR: In this paper, the electrochemical behavior of kryptand 222 at the interface between a mercury electrode and an aqueous solution is studied by the impedance spectroscopy, polarography, and cyclic voltammetry methods.
Abstract: The electrochemical behavior of kryptand 222 at the interface between a mercury electrode and an aqueous solution is studied by the impedance spectroscopy, polarography, and cyclic voltammetry methods. It is established that kryptand 222 possesses high surface activity at this interface. Adsorption parameters of kryptand 222 are found on the basis of the model of two parallel capacitors supplemented by the Frumkin isotherm by the regression analysis method. The potential dependences of the differential capacitance (C,E curves), calculated using these parameters satisfactorily agree with experiment. It is shown that the maximum in the C,E curves in the region of negative potentials is caused by catalytic process of hydrogen evolution.

Journal Article
TL;DR: In this paper, a catalytic polarographic method for determination of trace amounts of formaldehyde was proposed, and the detection limit of the method was found to be 0.041 mg·L~(-1).
Abstract: In a dil.H_2SO_4 medium,the redox reaction between KBrO_3 and methyl red was strongly catalyzed by trace amounts of formaldehyde,and at the same time,sensitive polarographic adsorption waves were produced at the dropping mercury electrode by either methyl red or its oxidation product at peak potentials of—0.57 V and—0.49 V(vs.SCE)respectively.The 2nd derivative of peak current(I″_p)of methyl red measured at—0.57 V kept a linear relationship with the concentration of formaldehyde present in the reaction system in the range of 0.2—6.5 mg·L~(-1).Based on these facts,a catalytic polarographic method for determination of trace amounts of formaldehyde was proposed.Detection limit of the method was found to be 0.041 mg·L~(-1).Value of RSD(n=8) of 1.8% was obtained at the concentration level of 2.5 mg·L~(-1)of for maldehyde.Recovery found by standard addition method were in the range of 97.0% to 104.0%.

Book ChapterDOI
04 Apr 2007

Journal ArticleDOI
TL;DR: The polarographic behavior of a series of 4-arylidene-2-phenyl-2oxazolin-5-one derivatives over a wide range of pH is reported and discussed in this article.
Abstract: The polarographic behaviour of a series of 4-arylidene-2-phenyl-2-oxazolin-5-one derivatives over a wide range of pH is reported and discussed. A mechanism for the electrode process is elucidated and confirmed via isolation and characterisation of electrolysis products.

Journal Article
TL;DR: In this paper, the electrochemical behavior of the herbicides acifluferen and fluorodifen was studied using differential pulse polarography in universal buffers of pH range 2.0 to 12.0.
Abstract: The electrochemical behavior of the herbicides acifluorfen and fluorodifen was studied using differential pulse polarography in universal buffers of pH range 2.0 to 12.0. The cathodic peak observed for the herbicides are attributed to the reduction of nitro groups and showed to be pH dependent. Differential pulse polarography at dropping mercury electrode was used to establish an electroanalytical procedure for the determination of the herbicides. Acifluorfen and fluorodifen in formulations, soils and grains. Quantitative measurements were successful in the concentration range of 1.25×10-5 to 2.8×10-9 M, the lower concentration representing the detection limit by differential pulse polarography.

Journal Article
TL;DR: In this article, a highly selective and rapid new anodic adsorptive voltammetric method was developed for the determination of trace amount of enoxacin at a carbon paste electrode (CPE).
Abstract: A highly selective and rapid new anodic adsorptive voltammetric method was developed for the determination of trace amount of enoxacin at a carbon paste electrode (CPE).Using JP-303 polarographic analyser the enoxacin was adsorbed on the surface of the CPE in 0.40 mol/L NaAc-HAc buffer solution(pH 4.5)yielding one oxidation peak at 1.17 V (vs.SCE).The linear relationship between the peak current and enoxacin concentration is obtained in the range of 4.0×10-9~4.0×10-7 mol/L (90 s accummulation).The correlation coefficient is 0.995.Its detection limit is 2.0×10-9 mol/L (S/N=3)for a 110 s accummulation.The electrode reaction mechanism of enoxacin was investigated.The proposed method was applied to direct determination of enoxacin in the capsules with satisfactory results.