Osteryoung pulse

Distortions of dc polarographic waves for SCOC appeared at concentrations close to 1x10 M. For 2x10 M Cys the distinct distortions were evident for drop times longer than 2 seconds. Similar distortions for PrThz appeared already.at 1 s drop time (Fig.l). On the other hand, at the same Cys concentration, well developed curves were obtained in all pulse voltammetric techniques (Fig.2). The techniques studied were normal pulse, differential pulse and the fast square wave voltammetry (oswv) according to Osteryoungs. Pulse width dependence of normal pulse voltammetric waves confirmed their diffusional character and forward and reverse current curves in square wave voltammetry indicated reversibility of the oxidation process aiding in the increased sensitivity of this technique. 

Osteryoung J and Murphy M M 1991 Normal and reverse pulse voltammetry at small electrodes Microelectrodes Theory and Applications (Nate ASI Series E vol 197) ed M I Montenegro, M A Queiros and J L Daschbach (Dordrecht Kluwer)... 

Osteryoung, J. Pulse Voltammetry, /. Chem. Educ. 1983, 60, 296-298. Additional information on stripping voltammetry is available in the following text. 

Tokoro R, Osteryoung J. 1982. [Study of the reduction mechanism of 1,2-dibromothane by reverse pulse polarography]. An Sim Bras Eletroquim Eletroanal 1 307-316. (Spanish)... 

A. Golcu, S.A. Ozkan, Electroanalytical determination of donepezil HC1 in tablets and human serum by differential pulse and Osteryoung square wave voltammetry at a glassy carbon electrode, Pharmazie 61 (2006) 760-765. 

Jan. 20, 1927, Cleveland, Ohio, USA - Aug. 10, 2004, Raleigh, NC, USA) Osteryoung received his bachelor s education at Ohio University and his Ph.D. at the University of Illinois. He was professor and Chairman of the Chemistry Department at Colorado State University, a professor at the State University of New York at Buffalo and research professor and Chair of the Department of Chemistry of North Carolina State University. He published about 225 original scientific papers, and was especially known for his papers on double potential step -> chronocoulometry, -> square-wave voltammetry, and room-temperature molten salt electrochemistry. He also initiated computer-controlled electrochemical measurements, which helped in developing and optimizing - pulse voltammetry. He served as an Associate Editor for the journal Analytical Chemistry. 

Osteryoung square-wave voltammetry — The protocol of square-wave voltammetry developed by - Osteryoung is based on a square-wave potential train with a frequency that for each forward potential pulse the DC electrode is stepped in the same direction by one increment, i.e., one step of the DC staircase ramp. 

Robert Osteryoung is picked out here for recognition because—apart from his pioneering work on low temperature molten salts—he is well known for his early work on pulse techniques (Chap. 8). He was the first to develop computers to control electrochemical experiments. Professor Osteryoung is a Head of Chemistry at North Carolina State University where unlike some great researchers, he is well known for his success as an able administrator. 

Figure 3. Nomal-pulse polarogram of 1 x 10 M Tl in 0.1 M KNO. [Reproduced with permission from E. Parry, R. Osteryoung, AnaL Chem., 37, 1634 (1965).)...

Osteryoung J and Murphy M M 1991 Normal and reverse pulse voltammetry at small electrodes Microelectrodes ... 

Note that the Ilkovic equation contains a term m, the mercury flowrate, which reflects the growth of the drop during the measurement process. In contrast the Parry-Osteryoung equation contains a term A for the surface area of the electrode as if this were a constant. A is for practical purposes a constant since the growth of the drop is negligible during the very short pulse. 

If the concentrations of the redox compounds in the solution or at the electrode surface are low, and better sensitivities are needed than those optimal for LSV and SCV, differential pulse (DPV), normal pulse (NPV) and Osteryoung square-wave voltammetries (OSWV) are more suitable [9a, 9b]. They allow better elimination of the capacitive/background currents and, therefore, the measurement of smaller faradic signals becomes easier. This is achieved either by sampling the current at the end of each pulse (OSWV, NPV) (Fig. 10.5.IE and F) or twice at the end and before pulse application (DPV) (Fig. 10.5.ID). 

K. AOKI, J. OSTERYOUNG and R. A. OSTERYOUNG (1927-2004) introduce differential double pulse polarography (1980) J Electroanal Chem 110 1... 

The form of SWV most electrochemists use today is based on work dating from 1969 [16] and principally developed by Osteryoung and coworkers using large amplitude pulses [11,17], such that a steady state is not achieved, and it has taken over a large part of the traditional domain of application of DPV. 

As a general rule, quantification limits of lO moll can be readily obtained with conventional (d.c.) polarography, whereas these limits may be reduced to lO moll or lower by using modern pulse polarographic techniques and particularly square wave (Osteryoung) polarography. 

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