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In this work a new and simple polarographic method has been established for the determination of trace elements present in tea. After digestion with acids, tea samples were analyzed using various electrolytes such as acetate and ammonia at different pH values in the presence or absence of EDTA. Thus, it was possible tochoosethe best medium for the determination of6 trace elements in one tea sample. Polarographic peaks of copper and iron could be separated in HAc at about pH =7 in the presence of EDTA and their quantities were determined. Ni and Zn peaks could be separated and determined in ammonia buffer at about pH= 10. Lead could be determined at pH= 2HAc electrolyte. Selenite, was determined from its hydrogen catalytic peak in KCl, pH= 2 medium in the presence of Mo (VI). The LOD was found as 2.4x10-7 for instead of (S/N=3).The trace element ranges in black tea were found as, Fe 35 μg/g, Cu 45 μg/g, Ni 19 μg/g, Zn 22 μg/g, Pb 28 μg/g and Se 77 μg/g.
Herrero CL, Mejuto MM, Rodriguez B, Martinez FB. Fluorimetric determination of selenium in foods, Ann. Bromatol. 1987;39: 133-138.
Eurola HM, Ekholm IP, Ylinen EM, Koivistoninen EP, Pekka E, Varo TP. Fluorimetric determination of selenium in foods, J. Sci. Food Agric. 1991;56:57-62.
Tahvonen R, Kumpulainen J. Lead and cadmium in berries and vegetables on the Finnish market, Fresenius J. Anal. Chem. 1991;340:242-245.
Somer G, Guliyeva G, Ekmekci G, Şendil O. Simultaneous determination of copper, lead, cadmium, zinc, and selenium in cow liver by DPP. Can. J. Chem. 2003; 81:31-36.
İnam R, Somer G. A direct method for the determination of selenium and lead in cow's milk by differential pulse stripping voltammetry, Food Chem. 2000;69:345-349.
Somer G, Ünal Ü. A new and direct method for the trace element determination in cauliflower by differential pulse polarography. Talanta. 2004;62:323-327.
Somer G, Kalaycı Ş. A new and simple method for the simultaneous determination of Fe, Cu, Pb, Zn, Bi Cr, Mo, Se and Ni in dried red grapes using differential pulse polarography. Food Anal. Met. 2015;8:604-608.
Somer G, Nakışcı A, Kalaycı Ş, Şahin F. Trace element determination in brassica oleraceae var. acephale by Differential Pulse Polarography. Turk J. Chem. 2006; 30:419-423.
Kalaycı Ş, Somer G. Factors affecting the extraction of fluoride from tea, application to tea samples, Fluoride. 2003;36(4):267-271.
King NM, Tsang MCK. Fluoride content of Chinese and black teas available in Hong Kong, Fluoride. 1987;20:18-21.
Fung KF, Zhang ZQ, Wong JWC, Wong MH. Assessment of trace metal distribution and contamination in surface soils of Hong Kong, Environmental Pollut. 1999;104:197-205.
Somer G, Özyörük G, Green ME. Determination of trace heavy elements in air particulates by differential-pulse polarography. Analyst. 1985;110:151-156.
İnam R, Somer G. An unusual polarographic behavior of Selenite in the Presence of Some Cations, Analytical Sciences. 1998;14:399-402.
İnam R, Somer G. Differential pulse polarographic determination of trace selenium (IV) and molybdenum(VI) using catalytic hydrogen wave, Talanta. 1999; 50:609-616.