Evaluation of Heavy Metal Presence in Agricultural Samples of Lactuca sativa and Trifolium alexandrinum Using Picosecond Laser-Induced Breakdown Spectroscopy and Flame Atomic Absorption Spectroscopy in Banha and Giza Governorates, Egypt

Abstract

This pioneering study utilizes Flame Atomic Absorption Spectroscopy (FAAS) and Picosecond Laser-Induced Breakdown Spectroscopy (Ps-LIBS) to quantify heavy metal contents in samples of Lactuca sativa L. and Trifolium alexandrinum L. collected from Banha and Giza, Egypt for the first time. In order to enhance the performance of Ps-LIBS, laser parameters were carefully optimized. Expressly, laser energy was set to 100 ± 5% J/cm², pulse duration was calibrated to 170 picoseconds, and 1064 nm Nd: YAG pulses were employed. This optimization facilitated the creation of linear LIBS calibration curves, a crucial element in ensuring precise elemental quantification and bolstering the overall analytical reliability. The assessment of pollution indices revealed concerningly high levels of copper, nickel, and cadmium consistently across all study sites. Lactuca sativa L. and Trifolium alexandrinum L. also demonstrated multiple metals’ bioaccumulation factors (>1), further underscoring the potential health risks associated with copper, nickel, and cadmium contents. Given these findings, it is imperative to recommend constructing a dedicated wastewater treatment facility to address Al Mansouria village’s environmental challenges in the Giza governorate.