Spectrochemical Analysis of Nutritional and Toxic Metals in Different Brands of Candies Using Advanced Diagnostic...

Candies are frequently consumed sweetened food products among children, and their consumption can expose them to potential toxins and contamination. The present study employed calibration-free-laser-induced breakdown spectroscopy (CF-LIBS) as a steadfast diagnostic technique to analyze the presence of nutritional and heavy metals in candies from various brands available in local markets in Haripur, Pakistan. A pulsed Nd-YAG laser was used to create a microplasma on the target surface. The emitted light was collected using a dedicated spectrometer to analyze and quantify the species present in the candies. The analysis revealed the presence of micronutrients, macronutrients, and trace toxic metals such as Ca, K, Mg, Fe, Na, Al, Pb, Cr, Mn, Zn, Cu, and Ni. The optimization of our LIBS system was achieved through a parametric dependence study. The confirmation of the assumption of local thermodynamic equilibrium was achieved by assessing McWhirter's criterion and considering the relaxation time and the diffusion length of atoms in plasma. The highest concentrations (measured in mg/kg) of Pb, Cr, and Mn were determined to be 15 mg/kg, 340 mg/kg, and 880 mg/kg, respectively. The levels of Pb and Cr were found to be well above the maximum accepted limit set by the WHO. Similarly, the concentration of Mn in S-4 and S-5 exceeded the permissible limits set by the WHO. However, Zn, Cu, and Ni were found within safe limits in all the collected samples. In addition, the abundance obtained through CF-LIBS was compared to the concentration of similar (duplicate) candies samples analyzed using a standard analytical technique like inductively coupled plasma-optical emission spectroscopy. Excellent harmony could be seen in both outcomes. Moreover, energy-dispersive X-ray spectroscopy (EDX) was also utilized to confirm the presence of detected toxins. The significance of our findings lies in creating awareness among the public about the health risks associated with consuming toxins through candies, thereby protecting numerous human lives.