Zinc (Zn) Analysis in Milk by Microwave Oven Digestion and Differential Pulse Anodic Stripping Voltametry (DPASV) Technique

Mohineesh Mohineesh,A Raina,J Raj,T D Dogra

doi:10.1051/e3sconf/20130139007

Mohineesh Mohineesh, A Raina + Show 2 more

Open Access

https://doi.org/10.1051/e3sconf/20130139007

Copy DOI

Abstract

Milk is very important component of human diet. The presence of over limit of heavy metal in milk may create significant health problems. In the present study, the direct determination of Zinc (Zn) heavy metal in milk samples of different brands was carried out by differential pulse anodic stripping Voltammetric technique at Hanging Mercury Drop Electrode (HMDE). Milk samples were processed by microwave oven digestion using HP/VHP Vessels and TFM Liners and nitric acid (HNO3 ).Determination of Zn was made in acetate buffer (pH 4.6) with a sweep rate (scan rate) of 59.5 mV/s and pulse amplitude 50mV by HMDE by standard addition method. The solution was stirred during pre-electrolysis at -1150mV (vs. Ag/AgCl) for 90 seconds and the potential was scanned from -1150V to +100V (vs. Ag/AgCl). The zinc ions were deposited by reduction at -1150 mV on HMDE. The stripping current arising from the oxidation of metal was correlated with the concentration the metal in the sample. .As a result the minimum level of Zn observed in the milk sample of different brands was determined as 2.28 mgL−1 .

Highlights

Milk is an important source of minerals including trace elements for suckling as well as for human nutrition
Milk samples were processed by microwave oven digestion using HP/VHP Vessels and TFM Liners and nitric acid (HNO3).Determination of Zn was made in acetate buffer with a sweep rate of 59.5 mV/s and pulse amplitude 50mV by Hanging Mercury Drop Electrode (HMDE) by standard addition method
The stripping current arising from the oxidation of metal was correlated with the concentration the metal in the sample. .As a result the minimum level of Zn observed in the milk sample of different brands was determined as 2.28 mgL-1

Summary

Introduction

Milk is an important source of minerals including trace elements for suckling as well as for human nutrition. [6] The other reasons for using DPASAV technique are: It has extremely low detection limits, and it works in the presence high salt concentrations It allows metal speciation and can differentiate between free and complexed metal ions. DPASV technique was used to determine Zinc metal in various milk samples of Delhi (India) using Hanging mercury. The most appropriate conditions were fixed to determine Zinc amount as an analytical application of DPASV on a HMD electrode

Materials and Methods

Results and Discussion

Conclusion