Research on Soluble Salts in Archaeological Ceramics From Marine Environments by Synchrotron Radiation X‐Ray Fluorescence Microanalysis

Soluble salts primarily composed of light elements are critical factors affecting archaeological ceramics from marine environments. The synchrotron radiation X‐ray fluorescence microanalysis (μ‐SRXRF), with technological upgrades or enhancements to the equipment's functionality, overcomes the limitations of traditional methods in terms of detection capability and precision, providing high‐precision elemental mapping analysis of light elements for intact samples. In this study, μ‐SRXRF combined multi micro‐analysis technics such as ultra‐depth‐of‐field microscopy, micro‐area X‐ray diffraction analysis, Raman spectroscopy, and scanning electron microscopy–energy dispersive X‐Ray spectroscopy (SEM‐EDS) conducts a detailed analysis of the soluble salts within the ceramic samples from the “Nanhai I” shipwreck. The results revealed that the distribution pattern of soluble salts is closely related to the internal structural characteristics of the ceramics and the micro‐structure and mineral phases are important factors influencing the distribution of soluble salts. Additionally, soluble salts can infiltrate the interior of ceramics by corroding the glaze layer or by directly passing through pore structures. As for the samples from the “Nanhai I” shipwreck, the sauce‐glazed ware and lead‐glazed pottery are more heavily affected by erosion compared to other types such as white‐glazed porcelain and celadon. Synchrotron‐based μ‐XRF demonstrates its unique and excellent performance, successfully achieving in situ, non‐destructive, fast, and high‐resolution elemental imaging of whole samples. The result provides a scientific foundation for studying the distribution characteristics of soluble salts within ceramics and for subsequent conservation efforts of cultural relics.