Laser-induced breakdown spectroscopy for multi-elemental analysis of Nerium oleander with atomic absorption...

This study presents a systematic quantitative multi-elemental investigation of four major plant organs (roots, stems, leaves, and flowers) of Nerium oleander using calibration-based Laser-Induced Breakdown Spectroscopy (LIBS), with the results validated by Atomic Absorption Spectroscopy (AAS). Plasma characterization was carried out using Boltzmann plot and Stark broadening analyses, while negligible self-absorption observed through the Hα emission line confirmed optically thin plasma conditions and reliable quantitative measurements. A total of nine elements were detected, including Fe, Zn, Mn, Ca, Mg, K, Na, Cu, and Ni, each exhibiting different concentration levels across the analyzed tissues. Compositional analysis using standard calibration curve-based LIBS demonstrated that elemental concentrations were non-uniform, showing marked variations between the different plant tissues. Among the detected elements, calcium emerged as the most prevalent across all tissues. The highest calcium concentration was observed in leaves (16,385 mg L^-1), followed by roots (12,092 mg L^-1) and flowers (11,185 mg L^-1). Root tissues exhibited elevated concentrations of Fe and Mn, reaching 1918 and 513 mg L^-1, respectively. In contrast, flowers showed the highest Mn concentration (1888 mg L^-1), while leaves were enriched in Mg (4445 mg L^-1) and K (3700 mg L^-1). The highest Na concentration was observed in stems (8025 mg L^-1). Trace metals, including Cu, Zn, and Ni, were detected at comparatively low concentrations, while Pb remained undetected in all samples. The strong agreement between LIBS and AAS measurements confirms the reliability of the proposed methodology and demonstrates the potential of LIBS as a rapid and non-destructive tool for elemental assessment of medicinal plants.