Presence of Toxic Metals in Chocolate

Pak. J. Anal. Environ. Chem. Vol. 10, No. 1 & 2 (2009) 48-52

Determination of Toxic Metals in Different Brand of
Chocolates and Candies, Marketed in Pakistan
Nusrat Jalbani1, Tasneem Gul Kazi2*, Hassan I. Afridi2 and
Mohammad Bilal Arain3
PCSIR Laboratories Karachi, Pakistan
National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan
Dept. of Mathematics & Basic Sciences, NED University of Engineering and Technology, Karachi 75270, Pakistan

In present study three toxic metals, cadmium (Cd), nickel (Ni) and lead (Pb) were determined in
chocolates and candy samples available in local markets of Hyderabad, Pakistan. Concentrations
of understudy toxic metals (TMs) were determined by electrothermal atomic absorption
spectrometry (ETAAS) prior to microwave assisted acid digestion. Validation of the methodology
was performed by standard addition method and conventional acid digestion on electric hot plate
to obtained TMs concentration, for comparative purpose to obtain results within the 95%
confidence level. No significant differences were observed for TMs obtained from both methods
(P = 0.05). The concentration of Cd, Ni and Pb were observed in chocolates and candy samples is
ranged as of 0.099 - 0.353, 1.45 - 4.33 and 1.11 - 2.48 µg/g, respectively. The results indicated that
cocoa-based chocolates have higher contents of TMs than milk- based chocolates and candies.
Keywords: Toxic metals, Chocolates, Candies, Atomic absorption spectrometry

Chocolate is an ingredient usually used in the
preparation of several foods (cakes, cookies, breads, ice
creams, etc.), which are consumed mainly by children.
Thus, the mineral content...