Evaluation of Inorganic Element Content and Safety of Selaginellae Herba Carbonisata Based on Different Processing Heating Durations

This study evaluated the inorganic element content and safety of Selaginellae Herba Carbonisata under different processing durations, including unprocessed crude drugs (SH-Cr), insufficiently (ISH-Ca), properly (SH-Ca), and excessively processed (ESH-Ca) samples. The contents of 39 elements were analyzed by ICP-MS, and the safety of key heavy metals (Pb, As, Cd, Cu) was assessed using exposure assessment, the Hazard Index (HI), and the Margin of Exposure (MOE). Results showed high concentrations of K, Fe, Mg, and Na, alongside beneficial trace elements (Al, Ca, Mn, Zn). Furthermore, Levels of Mg, K, Ca, Mn, Cu, Zn, Ga, Rb, and Au increased significantly with higher processing temperatures ( P 1), the potential introduction of lead and copper during processing warrants attention, highlighting the need to standardize raw materials and processing equipment. SH-Ca was identified as the optimal product due to its balanced elemental profile and safety compliance. In summary, these findings support quality control for carbonized herbal materials and provide insights for their potential applications in functional foods and dietary supplements. • Comprehensive profiling of 39 inorganic elements (including 4 heavy metals) in Selaginellae Herba under different processing durations, revealing temperature-dependent accumulation of Mg, K, Ca, Mn, Cu, Zn, Ga, Rb, and Au ( P 1). • Multivariate analysis revealed distinct differentiation between processed samples, with Ag, Pb isotopes, Sn and Cu being key discriminatory elements (VIP >1).