A new and direct method for the determination of trace elements in spinach using differential pulse polarography

•Using DP polarography it was possible to determine 7 trace elements in spinach.•Trace element determination in spinach is made first time using DPP in this work.•There is no need of preconcentration or extraction which is with risk of contamination.•Care has been taken during digestion so that the interference problems are solved.

For the trace determination of elements in spinach a new differential pulse polarographic (DPP) method is established. The polarograms were taken in various electrolytes and pH values in the presence of digested spinach sample. Trace element determinations were made in acetate and ammonia electrolytes at various pH values, with or without EDTA. Fe and Cu peaks could be separated and determined at pH 7, acetic acid electrolyte in the presence of EDTA. Ni and Zn peaks could be separated and determined in ammonia buffer at pH 10. Lead could be determined at pH 2 acetic acid and Mo (VI) was determined at pH 4 acetate buffer, EDTA medium. Selenite was determined from its hydrogen catalytic peak. The trace element in spinach was found as Fe 15 μg/g, Cu 17 μg/g, Ni 8 μg/g, Zn 27 μg/g, Pb 47 μg/g, Mo 43 μg/g, and Se 762 μg/g.