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

摘要

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.