5098

4794

كارشناسي ارشد

شيمي تجزيه

اصفهان: دانشگاه صنعتي اصفهان،دانشكده شيمي

1388

پانزده،104ص.:مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

علي اصغر انصافي

بهزاد رضايي

89/1/21

تقي خياميان،محمد سراجي

شيمي

ID4794

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Application of magnetohydrodynamic Hg thin film based graphite Electrode on voltammetry and their application for determination of Cd II Zn II Pb II at ultra trace level Zahra Nazari z nazari@yahoo com 9 February 2010 Department of chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Prof A A Ensafi Ensafi@cc iut ac ir Abstract In the first part of this project differential pulse anodic stripping voltammetry DPASV coupled with redox magnetohydrodynamics MHD to enhance the anodic stripping voltammetry ASV response has been shown to yield a quantitative simultaneous determination of lead cadmium and zinc ions determination in water samples using mercury thin film glassy carbon electrode The sensitivity was facilitated by using 20 0 mmol L 1 quinone as a new reagent to enhance ASV by redox MHD in the presence of a magnet This Lorentz force induces solution convection during the deposition step enhancing the mass transport of analytes to the electrode and increasing their preconcentrated quantity in the mercury thin film Therefore larger ASV peaks and improved sensitivities are obtained compared to analyses performed without a magnetic field to produce a high cathodic current which generates a significant Lorentz force Using 1 min as an accumulation time and accumulation potential 1 10 V detection limits of 0 05 0 09 and 2 3 ng mL 1 Cd II Pb II and Zn II has been established The calibration curves were constructed for 0 07 70 0 ng mL 1 Cd II 3 5 220 0 ng mL 1 Zn II and 0 1 60 0 ng mL 1 Pb II under the optimized conditions respectively In the second of this project A new carbon based mercury thin film electrode CBMFE consisting of screen printed carbon SPC on a low temperature co fired ceramic LTCC substrate was used for simultaneous determination of ultra trace amounts of cadmium II Zinc II and lead II using differential pulse anodic stripping voltammetry Analysis with CBMFE has very good reproducibility 4 and long term stability 500 measurement cycles The electrode can be prepared easily using an acetate buffer solution pH 4 0 containing 10 mmol L 1 mercuric nitrate and 50 mmol L 1 potassium thiocyanate with an applied potential of 0 90 V vs Ag AgCl saturated KCl for 60 s The calibration plot was linear over the range 0 5 60 0 ng mL 1 Cd II 8 0 200 0 ng mL 1 Zn II and 0 6 70 0 ng mL 1 Pb II Detection limits of 0 25 0 45 and 7 5 ng mL 1 were obtained for Cd II Pb II and Zn II respectively Keywords Permanent magnets Quinone Lorantz force Redox magnetohydrodynamic Carbon mercury film electrode Screen printed gold on a ceramic LTCC substrate Potassium thiocyanate PDF created with pdfFactory Pro trial version www pdffactory com

علي اصغر انصافي

بهزاد رضايي

تقي خياميان،محمد سراجي