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    Preconcentration and electroanalysis of copper at glassy carbon electrode modified with poly(2-aminothiazole)
    (2011) Çiftçi H.; Testereci H.N.; Öktem Z.
    Conducting poly(2-aminothiazole), PAT, was synthesized in acetonitrile with tetrabutylammonium tetrafluoroborate, TBAFB, as supporting electrolyte via constant potential electrolysis, CPE. Glassy carbon, GC, electrode was modified by immersing the electrode in a DMSO solution of PAT. Preconcentration of copper on polymer matrix was carried out at -0.7 V. The effects of preconcentration time and pH and Cu(II) concentration of the preconcentration solution on the stripping peak current of copper were studied.
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    Öğe
    Viscosity molecular weight determination of polyadenylic acid
    (1995) Usanmaz A.; Önal A.M.; Testereci H.N.
    In this study viscosity measurements of polyadenylic acid (PolyA) in aqueous solution were carried out under different conditions. In the absence of any additives, the polymer degraded during flow through the capillary of a viscometer or when standing still. Degradation during the former was more severe. The degradation of polyadenylic acid can be prevented by addition of an electrolyte such as KC1 to increase the ionic strength. However, in this case the deviation from linearity was still considerable at most ionic strength values. The best fit to the Huggins and Kraemer equations was obtained using a Tris-EDTA buffer solution with a final pH of 7.65. Estimation from intrinsic viscosity and weight-average molecular weight values gave K and ? as 2.04 X 10 5 and 0.89 from the equation ? = KM ? . The difference between Huggins (k 1 ) and Kraemer (k' 1 ) constants was close to 0.50 for all measurements. © 1995, Taylor & Francis Group, LLC. All rights reserved.