Arsenic voltammogram

SWV has been applied to study electrode reactions of miscellaneous species capable to form insoluble salts with the mercury electrode such as iodide [141,142], dimethoate pesticide [143], sulphide [133,144], arsenic [145,146], cysteine [134, 147,148], glutathione [149], ferron (7-iodo-8-hydroxyquinolin-5-sulphonic acid) [150], 6-propyl-2-thiouracil (PTU) [136], 5-fluorouracil (FU) [151], 5-azauracil (AU) [138], 2-thiouracil (TU) [138], xanthine and xanthosine [152], and seleninm (IV) [153]. Verification of the theory has been performed by experiments at a mercury electrode with sulphide ions [133] and TU [138] for the simple first-order reaction, cystine [134] and AU [138] for the second-order reaction, FU for the first-order reaction with adsorption of the ligand [151], and PTU for the second-order reaction with adsorption of the ligand [137]. Figure 2.90 shows typical cathodic stripping voltammograms of TU and PTU on a mercuiy electrode. The order of the... 

Figure 34. (A)Cyclic voltammograms of CoOx nanoparticles modified GC electrode in pH=7 solution at scan rate of 20mVs 1 In the absence (c) and presence of 40 pM H 202 (d). (a) and (b) are same as (c) and (d) for bare GC electrode. Reprinted from Analytica Chimica Acta, 594, A. Salimi, R. Hallaj, H. Mamkhezri, S. Soltanian, Nanomolar detection of hydrogen peroxide on glassy carbon electrode modified with electrodeposited cobalt oxide nanoparticles, 28, Copyrights (2007)with permission from Elsevier. (B) As (A) for 70 pM arsenic (III). Reprinted from Sensors and Actuators B, 129, A. Salimi, H. MamKhezri, R. Hallaj,S. Soltanian, "Electrochemical detection of an ultratrace amount of arsenic (III) at glassy carbon electrode modified with cobalt oxide nanoparticles, 248, Copyrights( 2008) with permission from Elsevier.

Arsenic, selenium and tellurium are three such elements which may be determined by cathodic stripping voltammetry after having been reduc-tively co-deposited with copper [38]. A characteristic of the cathodic stripping voltammograms of these three elements is that only a single current peak, which arises from the further reduction of the deposited analyte to As . Se" or Te", respectively. is observed. In this case the determination... 

Figure 20. The differential pulse cathodic (a) and anodic (b) stripping voltammograms of arsenic. The cel) solution was 0.1 mol/L HCl containing 2x10 mol/L Cu and 10 pg/L As. Voltage scan rate = 100 mV/s. j = -0.5. j V ...

---