Sachin Saxena

Estimation of heavy metals in multivitamin tablets by differential pulse anodic stripping voltammetry.

Differential pulse anodic stripping voltammetry (DPASV) was applied for the simultaneous determination of zinc and copper in multivitamin tablet (supradyn and centrum). Determination of the metals was made in ammonium acetate buffer (pH 4.5) with a scan rate of 0.01 V/s by Hanging Mercury Dropping Electrode (HMDE).The solution was stirred during electrolysis at -1.3 V for 300 s in the potential range of -1.3 to

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.

Sugar decolorization through activated carbon made from agricultural by-product based waste material

Activated carbons made-up from agricultural and industrial waste are new adsorbents, which seem very promising for water and air treatment. In this work, the activated carbons made-up from waste tea were tested for their ability to adsorb the sugar color from aqueous solution. The possible use of powdered activated waste tea (PAWT) as the adsorbents of sugar colour from their aqueous solutions and the effect of operating parameters were investigated. Increasing the temperature affects the adsorption capacity of the sugar colour. The adsorption process was found to be endothermic in nature. The physical and chemical properties of the activated carbon were analyzed using standard methods. The electrochemical study of one of the sugar colourant (glycine) is also performed. The results indicated that the powdered activated waste tea can be used as an effective adsorbent material for sugar decolourization.

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.