Optimal Sample Preparation for the Analysis of Micrometric Heterogeneous Samples

Area of Science:

• Materials Science
• Analytical Chemistry
• Art Conservation Science

Background:

• Microanalytical techniques are vital for analyzing complex cultural heritage materials.
• Noninvasive sample preparation is essential to prevent contamination and ensure accurate material identification.
• Varnishes, natural resins, and waxes are common surface materials in artworks.

Purpose of the Study:

• To develop and validate a noninvasive sample preparation method for microanalysis of cultural heritage materials.
• To assess the effectiveness of thin gold or carbon protective layers prior to resin embedding and microtoming.
• To optimize procedures for analyzing common artwork surface materials.

Main Methods:

• Application of thin gold or carbon protective layers on samples.
• Embedding samples in synthetic resin for microtoming.
• Analysis using optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), micro-Fourier-transform infrared spectroscopy (μFTIR/μSR-FTIR), and synchrotron X-ray diffraction (μSR-XRD).

Main Results:

• The proposed method, involving protective layers and resin embedding, is validated for varnishes (natural resins and wax).
• Successful microanalysis was achieved on an artwork sample using a combination of advanced techniques.
• The procedure ensures sample integrity for detailed microstructural and chemical analysis.

Conclusions:

• Thin gold or carbon protective layers are effective in noninvasively preparing complex cultural heritage samples for microanalysis.
• The method preserves sample integrity, enabling accurate identification of diverse materials.
• This technique supports advanced characterization of artworks and other sensitive materials.