University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Parviz Norouzi

Abbrev:
Norouzi, P.
Other Names:
Address:
Department of Chemistry; Tehran University Tehran 141556455, Iran
Phone:
+98 21 6112499
Fax:
+98 21 6495291

Citations 10

"Novel Method For Fast Determination Of Ultra Trace Amounts Of Timolol Maleate By Continuous Cyclic Voltammetry At Au Microelectrode In Flowing Injection Systems"
Sens. Actuat. B 2005 Volume 110, Issue 2 Pages 239-245
Parviz NorouziCorresponding Author Contact Information, E-mail The Corresponding Author, Mohammad Reza Ganjali, Ali Sepehri and Maryam Ghorbani

Abstract: A novel method for easy and fast detection of timolol maleate in flow-injection system has been introduced. It was used for analysis of timolol maleate in pure form as well as in its pharmaceutical formulations. The reported method is simple, precise, accurate, time saving and economic as compared to all previously reported methods. The best performance for measurement of timolol maleate was obtained at, pH 2.0, scans rate 300 V s-1, accumulation potential -500 mV and delay time 0.6 s. The advantages of the proposed detection method are, (1) the removal of oxygen from the test solution is not required any more, (2) the detection limit of the method is sub-micromolar, (3) this method is fast enough for determination of the drug compound, in a wide variety of chromatographic techniques. The potential waveform consists of potential steps for cleaning, accumulation and potential ramp that were continuously applied on an Au disk microelectrode (with a radius of 12.5 ?m). The detection limit of the method for timolol maleate was 1.58 ng mL-1. The relative standard deviation of the method at 1.0 x 10^-9 M was 2.3% for 20 runs. © 2005 Elsevier B.V. All rights reserved.

"Sub-second Accumulation And Stripping For Pico-level Monitoring Of Amikacin Sulphate By Fast Fourier Transform Cyclic Voltammetry At A Gold Microelectrode In Flow-injection Systems"
Microchim. Acta 2005 Volume 152, Issue 1-2 Pages 123-129
Parviz Norouzi, Gholam-Reza Nabi Bidhendi, Mohammad Reza Ganjali, Ali Sepehri and Maryam Ghorbani

Abstract: This study presents an easy and fast stripping voltammetric detection technique for the determination of amikacin sulfate in a flow-injection system. For a very sensitive determination, the currents were integrated for a whole potential scan range including oxidation and reduction of the gold surface electrode. The potential waveform, which consisted of potential steps for cleaning, stripping and potential ramp, was continuously applied to a gold disk ultra-microelectrode (with a diameter of 50 ?m). The greatest advantages of the proposed detection method are a) very low detection limit (picomolar level), b) removing oxygen from the test solution is not necessary, c) very fast and appropriate for monitoring drug compounds in a wide variety of chromatographic analysis methods. The detection limit for amikacin sulfate was 2.0 x 10^-11 M (?15 pg mL-1), and the relative standard deviation for 10 determinations of 1.0 ng mL-1 of amikacin was 3.2%. The effects of scan rate, accumulation potential, accumulation time and pH of eluent on the performance of the method were investigated. The results were used for the determination of amikacin sulfate in pharmaceutical preparations. © Springer-Verlag 2005.

"Fast Fourier Continuous Cyclic Voltammetry At Gold Ultramicroelectrode In Flowing Solution For Determination Of Ultra Trace Amounts Of Penicillin G"
Electroanalysis 2006 Volume 18, Issue 10 Pages 947-954
Parviz Norouzi*, Mohammad Reza Ganjali, Taher Alizadeh, Parandis Daneshgar

Abstract: In this work, for the first time a fast continuous cyclic voltammetry was used as a highly sensitive detection method for Penicillin G in a flow-injection system. A special computer-based numerical calculation method (using Fast Fourier Transformation) is introduced here for enhancing the analyte signal and noise reduction. During the measurements, the potential waveform (consists of potential steps for cleaning, stripping and potential ramp) was continuously applied on an Au disk microelectrode (with a radius 12.5 ?m in radius). The stripping time was less than 200 ms. Effects of rest potential, sweep rate, and delay time on the sensitivity of the method were investigated. The limit of detection of the method was 1.0 x 10^-11 M. The detection limit of the method is 660 times lower than the most sensitive reported method. The relative standard deviation of the method at 1.0 x 10^-7 M of Penicillin G was 2.7% for 10 runs.

"Sub-second Adsorption For Sub-nanomolar Monitoring Of Metoclopramide By Fast Stripping Continuous Cyclic Voltammetry"
Electrochem. Commun. 2005 Volume 7, Issue 4 Pages 333-338
Parviz NorouziCorresponding Author Contact Information, E-mail The Corresponding Author, Mohammad Reza Ganjali and Parisa Matloobi

Abstract: In this work a novel indirect method for the determination of metoclopramide (MET) in flow-injection systems by fast stripping continuous cyclic voltammetry (FSCCV) has been developed. The proposed method was used for the fast determination of metoclopramide in its pharmaceutical formulations. The developed technique is very simple, precise, accurate and time saving, compared to all of the previously reported methods. The effects of various parameters on the sensitivity of the method were investigated. The best performance was obtained within the pH value of 2.0 and sweep rate value of 20 V/s, accumulation potential of -700 mV and accumulation time of 0.1 s. The proposed method has some advantages, the greatest of which are: (1) removing of oxygen from the test solution is not necessary; (2) very low detection limit; and (3) it is fast enough for the determination of any such compound, in a wide variety of chromatographic methods. The potential waveform, consisting of the potential steps for cleaning, accumulation and potential ramp of analyte, was applied on an Au disk microelectrode (with a radius of 12.5 µm) in a continuous way. The detection limit of the method for metoclopramide was 1.0 x 10^-11 M (3 pg/ml). The relative standard deviation of the method at 1.0 x 10^-10 M was 2.0% for 8 runs.

"Sub-second Adsorptive Fast Fourier Transform Coulometric Technique As A Novel Method For The Determination Of Nanomolar Concentrations Of Sodium Valproate In Its Pharmaceutical Preparation In Flowing Solution Systems"
Biosens. Bioelectron. 2007 Volume 22, Issue 6 Pages 1068-1074
Parviz Norouzi, Simindokht Shirvani-Arani, Parandis Daneshgar and Mohammad Reza Ganjalia

Abstract: In this work, a novel electrochemical technique has been developed for determination of nanomolar concentration of sodium valproate in flow-injection systems. The detection was done by adsorptive fast Fourier transform coulometric (AFFTC), in which the potential waveform consists of potential steps for cleaning, accumulation, and a potential ramp that was continuously applied on an Au disk microelectrode. Moreover, a special computer program is introduced based on numerical method, for calculation of the analyte signal (which is the partial and total charge exchanges at the electrode surface) and noise reduction. The optimum parameters were: pH value of 2.0, scan rate value of 40 V s-;1, accumulation potential of 200 mV and accumulation time of 0.3 s. Detection limit of the method for sodium valproate was 9.0 x 10^-9 M. The relative standard deviation of the method at 1.3 x 10^-7 M was 2.0% for 10 runs.

"Selective And Non-Selective Determination Of Heavy Metal Ions In Flowing Solutions By Fast Stripping Cyclic Voltammetry"
Anal. Sci. 2004 Volume 20, Issue 3 Pages 519-526
Parviz Norouzi, Mansoor Namazian And Alireza Badiei

Abstract: A simple and fast stripping voltammetric detection method has been designed for selective and non-selective measurements of heavy metal ions in a flow-injection system. A special computer numerical method is introduced for calculating the analyte signal and noise reduction, where the signal is calculated based on the partial and total charge exchange at electrode surface. For a selective determination, the currents are integrated in the range of the oxidation and reduction of the analyte. For non-selective measurements, the integration range is set for the whole potential scan range (including oxidation and reduction of the Au surface). The time for stripping has been shown to be less than 300 ms. The main advantages of the detection method are as follows: first, removal of oxygen from the measured solution is not required; second, it is sufficiently fast for the determination of heavy metal ions in various chromatographic analysis methods. The limit of detection for tested ions was between 3 x 10^-9 and 6 x 10^-10 M, and the relative standard deviation at 50 ppb Pb2+ was 4.7% for 10 runs.

"Fast Fourier Transform Continuous Cyclic Voltammetry Development As A Highly Sensitive Detection System For Ultra Trace Monitoring Of Thiamine"
Anal. Lett. 2007 Volume 40, Issue 3 Pages 547-559
P. Norouzi; M. R. Ganjali; P. Daneshgar; A. Mohammadi

Abstract: In this work, a highly sensitive method for the fast monitoring of thiamine hydrochloride in flow-injection systems has been developed. The fast Fourier transform continuous cyclic voltammetry (FFCV) in flowing solution as a detection system was applied for the very fast monitoring of thiamine in its pharmaceutical formulations. This technique is very simple, precise, accurate, time-saving and economical, compared to all previous reported methods. The effects of various parameters on the sensitivity of the detection system were considered. The best condition was obtained within the pH value of 2, and scan rate value of 25 V s-1, accumulation potential of -400 mV, and accumulation time of 0.6 s. The proposed method has some advantages over other reported methods such as, there is no need for the removal of oxygen from the test solution, has a sub-nanomolar detection limit, and finally the method is fast enough for the determination of any such compound, in a wide variety of chromatographic methods. This research also introduces a special computer-based numerical method, for the calculation of the analyte signal and noise reduction. The electrode response was calculated based on partial and total charge exchanges on the electrode surface after subtracting the background current from that of noise. To obtain a sensitive determination, the integration range of currents was set for all the potential scan ranges, including oxidation and reduction of the Au surface electrode, while performing the measurements. The potential waveform, consisting of the potential steps for cleaning, accumulation and potential ramp of analyte, was applied on an Au disk microelectrode (12.5 µm in radius) in a continuous way. The detection limit of the method for thiamine was 1.0 x 10^-12 M. The relative standard deviation of the method at 1.0 x 10^-8 M was 2.2% for 8 runs.

"Fast Monitoring Of Nano-molar Level Of Gentamycin By Fast Fourier Transform Continuous Cyclic Voltammetry In Flowing Solution"
Anal. Lett. 2006 Volume 39, Issue 9 Pages 1941-1953
Parviz Norouzi; Mohammad Reza Ganjali; Leila Hajiaghababaei

Abstract: A novel method for the determination of gentamycin in flow-injection systems has been developed in this work. The principal advantages of this method are that it is rapid, simple, and possesses low detection limit. Some investigations were also done to find the effects of various parameters on the sensitivity of the proposed method. The conditions producing the performance were the pH value of 2, the scan rate value of 350 V/s, accumulation potential of (100 mV), and accumulation time of 0.9 s. Some of the advantages of the proposed method are: the removal of oxygen from the test solution is not required anymore, the detection limit of the method is sub-nanomolar, and finally, the method is fast enough for determination of such compounds, in a wide variety of chromatographic methods. We also introduce a special computer-based numerical method for calculation of the analyte signal and noise reduction. After subtracting the background current from noise, the electrode response was calculated, based on partial and total charge exchanges at the electrode surface. The integration range of currents was set for all the potential scan ranges, including oxidation and reduction of the Au surface electrode, to obtain a sensitive determination. The waveform potential was continuously applied on an Au disk microelectrode (12.5 ?m in radius). Detention limit of the method for gentamycin was found to be 1.0 x 10 -9 M. For 10 runs, the relative standard deviation of the method at 1.0 x 10 -7 M was 2.1%. Copyright © Taylor & Francis Group, LLC.

"Development Of Fast Fourier Transformation Continuous Cyclic Voltammetry As A Highly Sensitive Detection System For Ultra Trace Monitoring Of Penicillin V"
Anal. Biochem. 2007 Volume 360, Issue 2 Pages 175-181
Parviz Norouzi, Mohammad Reza Ganjali, Parandis Daneshgar, Taher Alizadeh and Ali Mohammadi

Abstract: Fast continuous cyclic voltammetry was used as a detection method for penicillin V in a flow injection system. Additionally, a special computer-based numerical calculation method (using fast Fourier transformation) providing enhancement of the analyte signal and noise reduction is introduced here. During the measurements, the potential waveform (consisting of the potential steps of cleaning, stripping, and the potential ramp) was continuously applied to an Au disk microelectrode (12.5 ?m in radius). In particular, the effects of accumulation potential, sweep rate, and delay time on the sensitivity and selectivity of the method were investigated. Eventually, the stripping time was found to be less than 300 ms, the detection limit of the method was 7.0 x 10^-12 M, and the associated relative standard deviation at 5.0 x 10^-6 M penicillin V was 2.3 for eight runs.

"Sub-second FFT Continuous Stripping Cyclic Voltammetric Technique As A Novel Method For Pico-level Monitoring Of Imipramine At Au Microelectrode In Flowing Solutions"
Acta Chim. Slov. 2006 Volume 53, Issue 4 Pages 499-505
Parviz Norouzi*, Mohammad Reza Ganjali, Behrouz Akbari-Adergani

Abstract: A novel method for the determination of imipramine in flow-injection systems has been developed. The method was used for the fast determination of imipramine in its pharmaceutical formulations and biological samples. The developed technique is very simple, precise, accurate, time saving and economic as compared to all previously reported methods. The effects of various parameters on the sensitivity of the method were investigated. The best performance was obtained with the conditions, pH value of 2.0, and sweep rate value of 60 V s-1, accumulation potential of 100 mV and accumulation time of 0.5s. In this work, we introduce a special computer based numerical method, for calculation of the analyte signal and noise reduction. The electrode response was calculated based on partial and total charge exchanges at the electrode surface after subtracting the background current from noise. The waveform potential consisting of potential steps for cleaning and accumulation of analyte, and potential ramp was applied on an Au disk microelectrode (with a radius of 12.5 ?m). The method was linear over the concentration range of 14-22400 pg mL-1 (r = 0.999) with a limit of detection and quantitation 4.55 and 14 pg mL-1, respectively. The method has the requisite accuracy, sensitivity, precision and selectivity to assay imipramine in tablets.