Potentiometric Sensor for Gadolinium(III) Ion Based on Zirconium(IV) Tungstophosphate as an Electroactive Material

Abstract

A new inorganic ion exchanger has been synthesized namely Zirconium(IV) tungstophosphate [ZrWP]. The synthesized exchanger was characterized using ion exchange capacity and distribution coefficient (Kd). For further studies, exchanger with 0.35 meq/g ion-exchange capacity was selected. Electrochemical studies were carried out on the ion exchange membranes using epoxy resin as a binder. In case of ZrWP, the membrane having the composition; Zirconium(IV) tugstophosphate (40%) and epoxy resin (60%) exhibits best performance. The membrane works well over a wide range of concentration from 1×10-5to 1×10-1M of Gd(III) ion with an over- Nernstian slope of 30 mv/ decade. The response time of the sensor is 15 seconds. For this membrane, effect of internal solution has been studied and the electrode was successfully used in partially non-aqueous media too. Fixed interference method and matched potential method has been used for determining selectivity coefficient with respect to alkali, alkaline earth, some transition and rare earth metal ions that are normally present along with Gd(III) in its ores. The electrode can be used in the pH range 4.0-10.0 for 10-1M and 3.0-7.0 for 10-2M concentration of target ion. These sensors have been used as indicator electrodes in the potentiometric titration of Gd(III) ion against EDTA and oxalic acid.

Synthesis, Characterization and Analytical Applications of Novel Potentiometric Sensor Based on Chromium(III)Boratotungstophosphate

“…Distribution coefficient studies: The preferential selectivity of electroactive material for a particular metal ion was evaluated by distribution coefficient values (Kd values). The Kd values for different metal ions like Sm(III), Mn(II), Ni(II), Co(II), Pb(II), La(III), Cu(II), Cd(II), Hg(II), As(III) were evaluated using the following formula [13]:…”

Synthesis, Characterization and Analytical Applications of Novel Electroactive Sensor based on Titanium(IV) Tungstovanadate for Determination of Cadmium

“…Distribution coefficient studies i.e. (Kd) values for different metal ions like Sm 3+ , Mn 2+ , Ni 2+ , Co 2+ , Pb 2+ , La 2+ , Cu 2+ , Cr 3+ , Cd 2+ , Hg 2+ and As 3+ were calculated by the formula given below [38]:…”

Development of a highly efficient gadolinium(III) potentiometric sensor using two aza-crown ether-based multiple diglycolamides (DGAs)

“…Determination of Gd in various environmental matrices can be carried out by using different analytical methods such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS) [9][10][11], electron spin resonance (ESR) spectroscopy [12,13], fluorescence [14], time-resolved fluorimetry [15], nuclear methods [16] and potentiometric methods [6,[17][18][19], etc. Most of these methods involve high-cost instruments, trained manpower, tedious sample preparations and are often time consuming.…”

“…Potentiometric sensors based on a polymeric membrane are widely reported for metal ions detection [20][21][22][23][24]. However, reports on the determination of gadolinium are limited [6,[17][18][19]. The ingredients for the preparation of the membranes include an ionophorea lipophilic organic molecule that binds the metal ion of interest and is the main reason for imparting selectivity towards the concerned metal ion, a chemically inert polymer to provide mechanical strength to the membrane, a plasticizer as a solvent to dissolve the ingredients and to provide the desired flexibility by lowering the glass transition temperature [25] and an ionic additive.…”