Differential Pulse and Square-Wave Cathodic Stripping Voltammetry of Xanthine and Xanthosine at a Mercury Electrode

Abstract

Adsorptive stripping voltammetry, based on adsorptive accumulation, is very sensitive technique for the determination of antibiotics, drugs and organic substances of biologically significance.In this context, Palecek 1-4 investigated the interaction of various purine and pyrimidine derivatives with a charged mercury electrode surface. Procedures based on this type of interaction have been proposed for the anodic stripping analysis of pesudouracil. 4 The cathodic adsorptive stripping voltammetric technique has been applied for the determination of a wide variety of nucleic acid bases 3,5,6 and their derivatives. [7][8][9] However, the interaction of such interesting biological compounds with metal ions has indicated that the chemical bond with the mercury is not only the case for stripping analysis technique.These compounds can be determined to ultra trace level as a complex form with voltammetrically active metal ions. [10][11][12] In a continuation of our previous studies 6-9,12 on the cathodic adsorptive stripping voltammetric determination of some nucleic acid components, it would be of interest to investigate the adsorption and preconcentration for ultratrace voltammertic measurements of Xan and Xano under the optimum conditions. The adsorption and preconcentration studies were followed by the application of DPCASV and SWCASV techniques for a trace determination of the investigated compounds. The step of determination is based on a strong interaction of the adsorbed Xan or Xano species with the mercury electrode surface forming the Hg(II)-xanthate compound. The adsorption and preconcentration of the Cu(II)-xanthate complex at the mercury electrode surface was also investigated. Experimental InstrumentationA Princeton Applied Research (PAR) Model 174A polarographic analyzer coupled with a PAR 174/50 ac polarographic interface and a PAR Model 510 (Lock-inamplifier) phase detector were used for ac voltammetric measurements. A PAR model 264 was used for cyclic and cathodic adsorptive stripping voltammertic measurements. PAR models 303 HMDE and an advanced X-Y recorder (model RE0151), equipped with the aforementioned instruments were used for all measurements. The voltammetric cell was maintained at 22 + 0.5˚C (5˚C for ac measurements). A saturated Ag/AgCl electrode and Pt wire electrode were used as reference and auxiliary electrodes. A stir-head bar and a PAR Model 305 stirrer were also used for the cyclic and stripping voltammetric techniques. Reagents and proceduresXan and Xano were obtained from Sigma and were used without further purification. Solutions containing different concentrations of the investigated compounds were prepared by dissolving a known amount of the chemically pure product in a specific volume of twice-distilled water. Britton-Robinson (B.R) buffer was brought to a constant ionic strength of 0.5 mol -1 by the addition of NaNO3, and adjusted to the desired pH. All of the chemicals were of reagent grade (Merck, Darmstadt). All metal salts were in the nitrate form. Twice-distilled deionized w...

Electrochemistry of Mercury

“…Accumulation of Cu(II) complexes with xanthine and xanthosine has also been utilized in stripping analysis [74]. Copper(II) indapamide complex was adsorptively accumulated at a HMDE and used for the determination of the ligand in the cathodic stripping step [75].…”

“…Xanthine and xanthosine were investigated on HMDE, applying out-of-phase ac and dc voltammetries [74]. It has been shown that both compounds are strongly adsorbed and interact chemically.…”

Nanocubic cobalt-containing Prussian blue analogue-derived carbon-coated CoFe alloy nanoparticles for noninvasive uric acid sensing

“…At present, the preparation of sensing materials tends to be micro- or nano-sized, 14 more specific and sensitive, 15 and detection methods have become more diverse. 16 For instance, gold nanoparticles were used to fabricate a disposable device to detect UA in artificial saliva, 17 uricase were incorporated in a copper nanozyme to facilitate the oxidation of UA, 18 indium-doped CeO 2 nanoparticles were prepared to achieve the determination of UA, 19 reduced graphene oxide was combined with the molecular imprinting technique to improve the selectivity toward UA, 20 and nano-boron-doped ceria was also developed as a UA sensor. 21 However, the use of noble metal increases the cost, the incorporation of enzymes decrease the storage period due to their inactivation, and the modification of molecularly imprinted polymers inhibited the electron transfer.…”

Ultratrace Xanthine Determination in Diluted Alkaline Electrolyte by Adsorptive Stripping Voltammetry at the Mercury Film Electrode

“…In heart perfusates or dialysates, elevated levels of purines can be an indicator of a heart attack because extracellular purines are also a marker of the level of cellular energy metabolism (Crushing and Mustafa 1991). Electroanalytical methods have been developed for the determination of xanthine (Owens and Dryhurst 1977;Goyal, Mittal, and Sharma 1994;Shubietah, Abuzuhri, and Fogg 1995;Ibrahim et al 1996;Cavalheiro and Brajter-Toth 1999;Spataru et al 2002;Zhao et al 2002;Sun et al 2003;Temerk et al 2003;Ibrahim et al 2004;Wang and Zhang 2005;Arslan, Yasar, and Kilic 2006;Xiao et al 2008). With the recent advancements in properties of adsorptive stripping voltammetry, new methodologies have been developed for adenine, thymine, guanine, ATP, and DNA using alkaline solution with less ionic strength as the supporting electrolyte .…”