Voltammetric Determination of Antibacterial Nitro‐Compounds at Activated Carbon Fibre Microelectrodes

2011

Electrochemical properties and diffusion-adsorption behavior of risperidone (RPN), an antiphyscotic drug, on hanging mercury drop electrode (HMDE) were carried out in BrittonRobinson (BR) buffer. Some electrochemical parameters such as diffusion coefficient, number of transferred electrons and proton participated to its reduction mechanism and surface coverage coefficient were calculated from the results of cyclic voltammetry, square-wave voltammetry and constant potential electrolysis. RPN was found to be reduced with single two-electron/two-proton quasi-reversible mechanism controlled mainly by adsorption with some diffusion contribution at the potential about -1.58 V (vs Ag|AgCl electrode). Experimental parameters were optimized to develop a new, accurate, rapid, selective and simple square-wave cathodic adsorptive stripping voltammetric (SWCAdSV) method for direct determination of RPN in pharmaceutical dosage forms, spiked human urine and human serum samples without time-consuming steps prior to drug assay. This method was based on the relation between the peak current and the concentration of RPN and it was recognized that peak current of reduction wave linearly changes with the concentration of RPN in the concentration range of 1.5-150 nM, when optimum preconcentration potential -0.65 V and optimum preconcentration time 60 s were applied. In this method, limit of detection (LOD) was found as 5.18 nM (2.12 ppb). The method was successfully applied to determine the RPN content of commercial pharmaceutical preparations, spiked human serum and spiked human urine. The method was found to be highly accurate and precise, having a relative standard deviation of less than 4.80% for all applications.

mentioning

confidence: 99%

Square-wave cathodic adsorptive stripping voltammetry of risperidone

Çakirer

Erk

2011

“…26 ). The abbreviation of m is the slope of the related calibration curve and s is the standard deviation of working concentration values of AT which is selected as 3.0 × 10 -7 and 5.0 × 10 -7 for AdsDPV and AdsSWV, respectively.…”

Section: Methods Validationmentioning

confidence: 93%

Electrochemical oxidation of atorvastatin and its adsorptive stripping determination in pharmaceutical dosage forms and biological fluids

Eskiköy

Durmuș

2011

Electrochemical behavior of atorvastatin (AT) and optimum conditions to its quantitative determination were investigated using voltammetric methods. Some electrochemical parameters such as diffusion coefficient, surface coverage of adsorbed molecules, electron transfer coefficient, standard rate constant and number of electrons were calculated using the results of cyclic voltammetry. A tentative mechanism for the oxidation for AT has been suggested. The oxidation signal of AT molecule was used to develop fully validated, new, rapid, selective and simple square-wave anodic adsorptive stripping voltammetric (AdsSWV) and differential pulse anodic stripping voltammetric (AdsDPV) methods to direct determination of AT in pharmaceutical dosage forms and biological samples. For the AdsDPV and AdsSWV techniques, linear working ranges were found to be 1.0 × 10 -7 -5.0 × 10 -6 and 3.0 × 10 -7 -5.0 × 10 -6 mol l -1 , respectively. The detection limits obtained from AdsDPV and AdsSWV were calculated to be 6.55 × 10 -8 and 1.53 × 10 -7 mol l -1 , respectively. The methods were successfully applied to assay the drug in tablets, human blood serum and human urine.

“…35 ). The abbreviation of s is the standard deviation of intercept of calibration curve and m is the slope of the related calibration curve.…”

Section: Methods Validationmentioning

confidence: 93%

Electrochemical behavior of disopyramide and its adsorptive stripping determination in pharmaceutical dosage forms and biological fluids

Öztürk

Durmuș

2010

Electrochemical behavior of disopyramide (DPA) and optimum conditions to its quantitative determination were investigated using voltammetric methods. Some electrochemical parameters such as diffusion coefficient, surface coverage of adsorbed molecules, electron transfer coefficient, standard rate constant and number of electrons were calculated using the results of cyclic and square-wave voltammetry. All studies were based on the quasi-reversible and adsorption-controlled electrochemical reduction signal of DPA at about -1.60 V vs Ag|AgCl at pH 10.0 in Britton-Robinson buffer. This adsorptive character of molecule was used to develop fully validated, new, rapid, selective and simple square-wave cathodic adsorptive stripping voltammetric (SWCAdSV) method to the direct determination of DPA in pharmaceutical dosage forms and biological samples without time-consuming steps prior to drug assay. Peak current of electrochemical reduction of DPA was found to change linearly with the concentration in the range from 7.15 × 10 -8 mol l -1 (0.024 mg l -1 ) to 1.43 × 10 -6 mol l -1 (0.49 mg l -1 ). Limit of detection (LOD) and limit of quantification (LOQ) were found to be 5.65 × 10 -8 mol l -1 (0.019 mg l -1 ) and 1.88 × 10 -7 mol l -1 (0.064 mg l -1 ), respectively. The method was successfully applied to assay the drug in tablets, human serum and human urine with good recoveries at about 100%.