کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7831906 1503279 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Electrodeposition of the Charge-Transfer Complex Generated during Electrooxidation of o-Tolidine and the Effects of Coexisting Chondroitin Sulfate
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Electrodeposition of the Charge-Transfer Complex Generated during Electrooxidation of o-Tolidine and the Effects of Coexisting Chondroitin Sulfate
چکیده انگلیسی
The electrochemical quartz crystal microbalance (EQCM) technique was used to investigate the electrodeposition of the charge-transfer complex (CTC) generated during electrooxidation of o-tolidine (o-TD) in Britton-Robinson buffers and the effects of coexisting chondroitin sulfate (CS). A V-shaped frequency response to the cyclic voltammetric switching of o-TD indicated the precipitation and dissolution of the poorly soluble CTC, an oxidation intermediate, formed at the Au electrode during the redox switching of o-TD in a neutral or a weakly acidic medium (pH=4.07-6.50). The effects of potential scan rate, solution pH, and several supporting electrolytes were examined. The depth of the V-shaped frequency curves (-Δf0V) was related to the supporting electrolyte used, with a decreasing sequence for −Δf0V as 0.20 mol·L−1 NaNO3 > 0.20 mol·L−1 NaClO4 > 0.10 mol·L−1 Na2SO4. The −Δf0V response to the redox switching of the CTC/o-TD “couple” was enhanced by the introduction of CS because of the formation of the CTC-CS adduct, as also characterized and supported by UV-Vis and FTIR spectrophotometry. The molar ratio (x) of the CTC to CS in the adduct and the electrode-collection efficiency of the CTC (η) were estimated using EQCM. The values of −Δf0V increased with the increase in CS concentration, with a linear range from 0.75 to 15.2 μmol·L−1, and a detection limit down to 50 nmol·L−1. The new method proposed for CS assay was characterized by a dynamically renewed surface of the detection electrode.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Physico-Chimica Sinica - Volume 24, Issue 2, February 2008, Pages 230-236
نویسندگان
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