Preconcentration of f-Elements from Aqueous Solution Utilizing a Modified Carbon Paste Electrode

Abstract

An evaluation using paraffin oil based, Acheson 38 carbon paste electrodes modified with α-hydroxyisobutyric acid (HIBA) to preconcentrate f-elements cathodically is described. The modified paste was made by directly mixing solid HIBA into the carbon paste. A chemically reversible cyclic voltammogram for HIBA was observed on this modified carbon paste, which was found to be a non-Nerstian, single electron transfer process. Lanthanides (less promethium) were found to accumulate onto the electrode surface during a 30 s electrodeposition step at -0.4 V vs Ag/AgCl from 0.1 M LiCl. The elements were then stripped off into a 2% HNO(3) solution by an oxidative step at +0.8 V vs Ag/AgCl; quantitative removal from the electrode was confirmed by ICPMS. Ultratrace solutions with initial concentrations down to 5 parts per quadrillion (ppq) were preconcentrated in 5 min above our instrumental limit of detection (LOD) of around 1 ppt for lanthanides.

Electro-catalytic activity of multiwall carbon nanotube-metal (Pt or Pd) nanohybrid materials synthesized using microwave-induced reactions and their possible use in fuel cells

“…While in acid medium using the platinum composite, the average E a is much less for the methanol oxidation [1, 6]. Formic acid oxidation on platinum composite showed much lower E a than reported earlier[37] and average E a values for palladium composites were comparable with literature values [38]. …”

Simultaneous electrochemical sensing of thallium, lead and mercury using a novel ionic liquid/graphene modified electrode

“…Chemically modified matrices are usually utilized to increase the surface area, conductivity and sensitivity of electrochemical sensors and to improve selective interactions between sensing layer and analytes [22][23][24]. Since the first use of carbon paste electrode (CPE) by Adams (1958) [25], it has been widely applied in the electroanalytical community due to its low cost, ease of fabrication, flexible substrate for modification, high sensitivity, renewable surface and etc [26]. Generally, the concept of a paste made up with carbon material and a non-conductive and inert binder.…”

Electroanalysis and Simultaneous Determination of 6-Thioguanine in the Presence of Uric Acid and Folic Acid Using a Modified Carbon Nanotube Paste Electrode

“…Carbon paste electrode (CPE) is a special kind of heterogeneous carbon electrode consisting of mixtures prepared from carbon powder and a suitable water-immiscible or non-conducting binder. [24][25][26] The use of carbon paste as an electrode was initially reported in 1958 by Adams. 27 In later researches a wide variety of modifiers [28][29][30][31] have been used with these versatile electrodes.…”