6405

5979

كارشناسي ارشد

شيمي تجزيه

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

1390

دوازده،50ص.: مصور،نمودار

ص.ع.به فارسي و انگليسي

علي اصغر انصافي

بهزاد رضايي

23/9/90

تقي خياميان، محمد تقي جعفري

شيمي

ID5979

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Tiron and p Aminophenol Modified Carbon Nanotubes Paste and Carbon Nanotubes Glassy Carbon Electrodes as Electrochemical Sensors for Determination of Hydrazine Mahsa Lotfi m lotfi@ch iut ac ir Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiAli A Ensafi Email Ensafi@cc iut ac irAbstract Hydrazine is used as an oxygen scavenger in industry and has been found to havewide applications as an antioxidant a photographic developer and an insecticide It is alsoused as a fuel in fuel cells due to its high capacity and lack of contamination In addition hydrazine is very important in pharmacology because it has been recognized as a carcinogenicand hepatotoxic substance which affects liver and brain glutathione Adverse health effectson people living near hazardous waste sites caused by hydrazine and its derivatives have beendescribed in the literature and the maximum recommended level of hydrazine in tradeeffluents is 1 g mL 1 In this work we describe quantitative determination of hydrazine using voltammetric methodat a poly tiron multiwall carbon nanotubes modified glassy carbon electrode surface Hydrazine does not show a measurable oxidation peak on bare GCE however cyclicvoltammetry of hydrazine at poly tiron multiwall carbon nanotubes modified glassy carbonelectrode surface shows enhanced electrooxidation signals The suitable electronic propertiesof MWCNTs suggest that they have the ability to promote charge transfer reaction when usedas an electrode Under the optimum conditions at pH 8 0 linear sweep currents increased inthe ranges of 10 3540 mol L 1 the detection limit for hydrazine is 1 8 mol L 1 the proposedmethod was applied to determine hydrazine in real samples In the second part A sensitive and selective electrochemical method for the determination ofhydrazine was developed using a p aminophenol modified multi wall carbon nanotubes pasteelectrode p APMWCNTPE The modified electrode exhibited good electrocatalytic activityfor electrochemical oxidation of hydrazine in the pH 7 00 phosphate buffer solution PBS The diffusion coefficient D 8 0 10 5 cm2 s 1 and the kinetic parameter such as the electrontransfer coefficient 0 66 of hydrazine at the surface of p APMWCNTPE were determinedusing electrochemical approaches The catalytic oxidation peak currents showed a lineardependence on the hydrazine concentration and a linear analytical curve was obtained in therange of 0 5 175 M of HZ with a correlation coefficient of 0 9975 The detection limit S N 3 was estimated to be 0 3 The RSD for 0 7 and 5 0 M HZ were 1 1 and 1 7 respectively The modified electrode showed good sensitivity selectivity and stability It wassuccessfully applied for the determination of HZ in real samples Key WordsHydrazine Multiwall carbon nanotubes modified electrode Tiron p Aminophenol

علي اصغر انصافي

بهزاد رضايي

تقي خياميان، محمد تقي جعفري