Determination and validation method of molybdenum by adsorptive catalytic stripping voltammetry at lead film electrode

Abstract

Abstract:A new, selective, sensitive and accurate method for determination of molybdenum by adsorptive catalytic stripping voltammetry was described. The method is based on catalytic reduction of adsorbed Mo(VI)-ARS complex onto the lead film electrode in the presence of chlorate used as oxidizing agent. The instrumental and solution parameters affecting the peak current were optimized. The calibration graph is linear between 2.65-20.00 µg/L Mo(VI) and limit of detection is estimated as 0.79 µg/L. The proposed method was applied to drinking water samples with satisfactorily recovery results and the uncertainty calculation of the method was performed.

Carbon nanotubes as a suitable material for electrochemical sensor used in voltammetric determinations of titanium

“…When analyzing the conditions of lead film formation in many procedures described in the literature, it was observed that the potential applied to the electrode being the substrate for the film assumed a different value from − 0.65 V in the negative direction up to − 1.7 V (Bobrowski et al 2008;Bobrowski et al 2018;Deniz et al 2017;Gęca et al 2016;Grabarczyk and Adamczyk 2019;Korolczuk et al 2014;Tyszczuk-Rotko et al 2014). As for the adsorption of Ti (IV) complexes on the surface of the working electrode in various procedures described in the literature, the potential also changed in a wide range depending on the working electrode and the complex (Bobrowski et al 2009;Cui et al 2013;Croot 2011;Gawryś and Golimowski 2001;Gawryś and Golimowski 2003;Grabarczyk and Wasąg 2015;Pereira and Pereira 1999;Romanus et al1991;Stadlober et al 1996;Vukomanovic and Loon 1994;Wasąg and Grabarczyk 2016;Zhao et al 1995).…”

“…In recent years, the literature has described many different working electrodes which use the formation of metallic films, among others lead film electrodes (PbFE). The formation of these electrodes can take place both ex situ and in situ (Bobrowski et al 2008;Bobrowski et al 2018;Deniz et al 2017;Gęca et al 2016;Grabarczyk and Adamczyk 2019;Korolczuk et al 2014;Tyszczuk-Rotko et al 2014). In the case of in situ, we add the salt of the lead from which the film is to be formed to the sample.…”

“…Regardless of the method of film metal electrode creation, a very important element is the electrode acting as the substrate on which the film is created. Such an electrode in the case of PbFE is most often a glassy carbon electrode (Deniz et al 2017;Gęca et al 2016;Grabarczyk and Adamczyk 2019;Tyszczuk-Rotko et al 2014) and less frequently carbon paste electrode (Korolczuk et al 2014). The aim of our research was to find another material competitive to glassy carbon, acting as a substrate for lead film electrode, allowing to improve the parameters of procedures for the determination of trace amounts of analytes.…”