A Feather-Trode Sensor for Detecting Lead Ions
Elmer R.E. Mojica1, Arlene B. Tocino2, Jose R.L. Micor2, and Custer C. Deocaris2,3,4*
1Institute of Chemistry, University of the Philippines Los Baños, College, Laguna, Philippines
2Department of Chemistry and Biotechnology, School of Engineering, University of Tokyo, 7-3-1, Hongo, Tokyo, Japan
3National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi,
Tsukuba Science City, Ibaraki, Japan
4Atomic Research Division, Philippine Nuclear Research Institute
Commonwealth Avenue, Diliman, Quezon City, Philippines
Feathers have sulfur-containing proteins that could accumulate heavy metals. A method for the determination of trace amounts of lead ions using chicken feather-modified electrode is described. The modified electrode is prepared by mixing ground chicken feathers with graphite powder and mineral oil. The accumulation step performed by immersing the electrode in lead (II) solution under open circuit and its response is evaluated with respect to pH and accumulation time. The lead (II) adsorbed on the electrode surface was determined voltametrically using sodium hydroxide solution as supporting electrolyte. The response is evaluated in terms of deposition time and deposition potential. The electrode composition and regeneration methods were also taken into account. The best conditions for the preconcentration step were pH 6.0 and 3 min accumulation time while 90 sec deposition time and -120 mV deposition potential gave the optimum result. The modified electrode that contained 10% feathers gave the highest signal and multiple stripping allows the removal of the adsorbed lead ions in the electrode surface. Linear response was observed from 1 to 10 mg/L (r2 = 0.996). The detection limit was found to be 0.59 mg/L while relative standard deviation from a series of 5 readings using 5 and 10 mg/L were 2.43% and 3.75%, respectively
Lead (Pb) is one of the most common heavy metals in the environment. Lead determination is important and urgent because of its toxic effects on human health. There is an increasing attention on the determination of trace. . . .
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