Soami Piara Satsangee

Electro Chemical Determination of Pb (II) Ions by Carbon Paste Electrode Modified with Coconut Powder

Coconut powder was used as modifier for carbon paste electrode for voltammetric determination of lead ions in aqueous samples. Different parameters like electrode composition, different electrolytes, electrolyte concentration, different pH values, deposition time and deposition potential were optimized for application of Coconut powder modified electrodes. The use of 0.2M HCl as supporting electrolyte and 20 % (w/w) modifier, deposition time 390 sec and deposition potential –1800mV gave an optimum current response for lead (II) solution. Results showed that the modified carbon paste electrode can determine Lead with better sensitivity in aqueous solutions.

Agricultural by-product based carbon paste sensor for the trace determination of heavy metals Pb and Cd by adsorptive stripping voltammetry

Low cost agricultural byproduct based sensors have opened new branch and equipped us with fabricated highly sensitive tools for the analysis and administration in food and water industries. They not only lowered the cost with reliable trace determinations but also are ecofriendly in nature. This paper reports utilization of bagasse (sugarcane waste) as a biomaterial used in the sensor for the detection of Pb and Cd toxic metals. The electrochemical technique was used for the performance study of the bagasse based carbon paste sensor. Surface characterization of modifier was carried using cyclic voltammetry, BET analysis, SEM and FTIR studies. The BET analysis reveals the pore distribution of bagasse falls in the mesoporous domain. The specific surface area are typically found as Sbet = 89.3 m2/g. In order to find the adsorption phenomenon of the characterized modifier and its interaction with the heavy metals, the bagasse modified carbon paste electrode was fabricated and studied by adsorptive stripping voltammetry technique. The fabricated electrode offered high sensitivity towards metals estimation and optimization of the electrochemical parameters were obtained with reference to amount of modifier, accumulating electrolyte, accumulation time, pH and supporting electrolyte. The effect of surfactants on the determination of the ions has been investigated with CTAB, SDS and Triton X-100. Analysis of Pb and Cd under optimized conditions with acetate buffer of pH 6 as accumulating solvent, hydrochloric acid as stripping electrolyte at a scan rate of 50mV/s resulted in stripping responses with good linearity. Linear calibration curves were obtained in the concentration ranges of 100–600 μgL−1 and 500–1200 μgL−1, respectively, for lead and cadmium at an accumulated time of 10 min with limits of detection 10.1 and 170.64 μgL−1.

Voltammetric determination of wedelolactone, an anti-HIV herbal drug, at boron-doped diamond electrode

AbstractBoron-doped diamond electrode has been utilized for the study of electrochemical behaviour of an anti-HIV herbal drug wedelolactone in Britton-Robinson buffer (pH-2.5) by square-wave and cyclic voltammetry techniques. The response characteristics of cyclic voltammetry and square wave voltammetry showed a remarkable increase in the anodic peak current and electrochemical impedance spectroscopy revealed a lowering in charge transfer resistance at the boron-doped diamond electrode as compared to the glassy carbon electrode that can be attributed to the higher sensitivity of boron-doped diamond sensor. Cyclic voltammetry at the boron-doped diamond surface revealed the oxidation of wedelolactone with two oxidation peaks (P1 and P2) with Ep1= 0.4V and Ep2=1.00 V with scan rate varying from 10 - 220 mV/s and exhibits diffusion-controlled process. Based on the electrochemical measurements, a probable oxidation mechanism has been deduced and the electrode dynamics parameters have been evaluated. The effect of concentration on the peak currents of wedelolactone was found to have a linear relationship within the concentration range of 50–700 ng/mL. The LOD and LOQ were found to be 43.87 and 132.93 ng/mL respectively. The applicability of the proposed method was further scrutinized by the successful determination of wedelolactone in real plant samples. Graphical AbstractVoltammetric method for the determination of an anti-HIV herbal drug Wedelolactone was studied at boron doped diamond sensor. The redox mechanism was proposed and electrode dynamics parameters were explored. The two oxidation peaks were observed (p1 and p2) due to presence of dihydroxy and phenol moiety attached to the ring.

Real Time Measurement of Biosorption Efficiency of Chemically Modified Coconut Powder for Pb(II) and Cd(II) Using Open Circuit Potential

Abstract The present communication reports a new method for the potentiometric determination of adsorbent efficiency of coconut shell powder for removal of lead and cadmium from water. A three-electrode system containing metal-coated copper wire electrode was used as a working electrode. At equilibrium Open Circuit Potential (OCP) values represents metal ion concentration in solution. With the addition of coconut powder an appreciable decrease in the OCP was observed, which is associated with the reduction of the metal ion concentration due to the uptake of metal ions by the coconut powder. Chemical modification of coconut biomass was carried out by graft co-polymerization of acrylic acid. Modified biopolymer has been characterized using FTIR technique. An increase in the adsorbent efficiency of the biomass was observed by graft-copolymerized biopolymer i.e. from 54.4 mg/g to 122.1 mg/g and 58.8 mg/g to 141 mg/g respectively for Pb (II) and Cd (II) ions. The OCP based method provides an easy and simple approach for real time measurement of adsorption efficiency, which is a low cost and less time consuming process.