Centrifugation assisted digestion for simultaneous voltammetric determination of ultra trace metal ions in water and milk samples

•Centrifugation assisted digestion for metal ion detection.•Simultaneous determination of six metal ions.•Simple method for sample preparation with minimum matrix effects.•Statistical Analysis for reliability of data.

The present work was aimed to optimize various instrumental and experimental parameters for development of simple and sensitive method for determination of some toxic and essential metal ions in milk and water samples. Differential Pulse Stripping Voltammetric technique was employed for the determination of Pb2+, Cd2+, Zn2+ and Co2+ at Hanging Mercury Drop Electrode (HMDE) and Hg2+ and As3+ at Gold- Rotatory Disk electrode (Au-RDE) respectively. The voltammetric analysis was performed after chemical mineralization of the samples by centrifugation assisted digestion. The results obtained were subjected to statistical analysis and concentrations were found above or around the permissible limits. Under the optimized conditions the limit of detection of metal ions was found to be 0.006 μg L−1 (Pb2+), 0.007 μg L−1 (Cd2+), 0.047 μg L−1 (Co2+), 0.013 μg L−1 (Zn2+), 0.001 μg L−1 (Hg2+) and 0.003 μg L−1 (As3+). The developed method produces a simple, rapid, suitable, economical and precise determination of these metal ions with low detection limit and minimum matrix effect.

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