Comparative analysis of digestion methods for quantifying heavy metals in plum orchards

Abstract

Increasing interest in healthy food among the population raises concerns about heavy metals in fruit and their impact on public health. To assess this issue, this study presents a comparative analysis of digestion methods for quantifying heavy metals in plum orchards managed under conventional and ecological practices in the “Adamachi” Farm district of Iasi University of Life Sciences (IULS). We evaluated and optimised two wet digestion methods - in an open system and microwave-assisted - to determine the concentrations of heavy metals, such as copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), and cadmium (Cd), which pose environmental and health risks. The metal concentrations were measured using an atomic absorption spectrophotometer, according to standard methods. Microwaveassisted digestion was more efficient and faster than the conventional method (in an open system). The ecologically managed orchards showed a lower heavy metal content overall, with the exception of Cu levels, due to the Cu-based treatments. By determining the estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) for both children and adults, the potential health risks from heavy metals were determined. There were no related associated risks to human health (THQ and HI < 1), and the accumulated metals in plum fruit samples showed that the EDI values followed the descending order of Cu > Zn > Ni > Pb > Cd. The analysis revealed non-significant differences for most data obtained after processing using the two methods. These results highlight the importance of selecting the optimal digestion methods for heavy metal analysis in plums and sustainable agricultural practices to safeguard the environment and consumer health from heavy metal contamination.