Characterization of Medicinal Amber Via Multispectral Analysis Combined with ICP-MS

BAI Donghan ,  

LI Zerun ,  

XIN Xueying ,  

LUO Lu ,  

摘要

ObjectiveTo systematically investigate the identification characteristics of medicinal amber, elucidating its microscopic features, crystal structural properties, and elemental composition, thereby providing a scientific foundation for quality control and authenticity verification.MethodsThirty-nine batches of amber samples were collected and analyzed through integrated techniques including morphological analysis, microscopic identification, powder X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and inductively coupled plasma mass spectrometry (ICP-MS) to evaluate their morphological attributes, phase composition, molecular vibrational modes, and trace element profiles. Among them, the XRD experiment used Cu Kα radiation (λ=1.5406 Å), with a scanning angle range of 10° to 70° (2θ) and a step size of 0.02°; the Raman spectroscopy experiment employed a 785 nm laser, with a spectral measurement range of 3 400 to 50 cm-¹, a laser power of 300 mW, a laser intensity of 30%, and a scanning time of 100 to 1 000 ms; the infrared spectroscopy experiment used a carbon-sulfur lamp, with a scanning range of 4 000 to 500 cm-¹, a resolution of 4 cm-¹, and 3 scans; the ICP-MS experiment utilized an RF power of 1.2 kW, a double-pass cyclonic spray chamber, a sample introduction system flow rate of 0.7-1.0 L·min-1, and an auxiliary gas flow of 0.2 L·min-1.ResultsUnder orthogonal polarized light microscopy, medicinal amber exhibited an isotropic homogeneous structure, with partial samples containing inorganic impurities such as AsS and SiO₂. FTIR spectra revealed characteristic absorption peaks at 2 932-2 939 cm⁻¹ (C-H stretching vibrations), 1 705-1 728 cm-¹ (C=O stretching vibrations), and 880-887 cm-¹ (C=C deformation vibrations), confirming the oxidative polymerization of terpenoid resin. Raman spectroscopy further identified distinctive peaks at 2 925 cm-¹, 2 870 cm-¹ (saturated C-H stretching), and 1 648 cm-¹ (C=C stretching), consistent with the structural features of oxidized-polymerized resin. ICP-MS analysis demonstrated that S, Al, Si, Fe, Na, and Ca were the predominant trace elements in medicinal amber.ConclusionThis study comprehensively evaluated medicinal amber's morphological, crystallographic, molecular, and elemental characteristics through multimodal analytical techniques. The findings establish a robust framework for establishing quality standards for medicinal amber and distinguishing it from synthetic resin imitations, offering critical data support for pharmacopeial revisions.

关键词

Medicinal amber;Multispectral analysis;Elemental profile;quality evaluation

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