Ophicalcitum revealed: composition, safety, and rapid quality control by multi-spectroscopy

Ophicalcitum is a traditional hemostatic mineral drug. It requires precise quality control and safety assurance to guarantee clinical efficacy and sustainable use. This study aims to elucidate its mineralogical composition, quantify contamination levels, and assess associated health risks. We employed micro-confocal Raman, X-ray diffraction (XRD), automated mineral identification and characterization system (AMICS), thermogravimetric-differential scanning calorimetry (TG-DSC), and inductively coupled plasma mass spectrometry (ICP-MS) to resolve mineral speciation, spatial distribution, and major element abundance. Additionally, near-infrared partial least squares (NIR-PLS) models were developed for rapid, non-destructive quantification of key components. Raman spectroscopy and XRD identified calcite, dolomite, serpentine, chlorite, and magnetite. AMICS revealed that Ca is shared mainly among calcite, diopside, and dolomite, while Mg occurs chiefly in olivine, diopside, and dolomite. TG-DSC identified but did not quantify carbonates. ICP-MS detected elevated levels of Ca and Mg, along with Fe, Al, Si, and frequent occurrences of Cu, Pb, and As.The water-flying method significantly reduced Cu and Pb content; calcination with vinegar or water quenching removed As and Cr. Statistical analysis showed a positive correlation between Cu-Pb-Zn and an inverse correlation with CaMg. Orthogonal partial least squares discriminant analysis (OPLS-DA) successfully distinguished Ophicalcitum from Stalactitum based on Ca and Mg content, and optimized NIR-PLS provide rapid green assays. Overall, this study clarifies the composition of Ophicalcitum and verifies the safety of its processed products. It also delivers an analytical blueprint for the rapid quantification and quality control of mineral-derived medicines.