Characterizing noninvasively conservation status of historical wet collections using spatially offset Raman...

Area of Science:

• Analytical Chemistry
• Heritage Science
• Spectroscopy

Background:

• Natural history collections rely on fluid-preserved specimens, facing conservation challenges from chemical and physical degradation.
• Current methods for assessing preservation fluid quality are often limited in scope.

Purpose of the Study:

• To apply handheld spatially offset Raman spectroscopy (SORS) for noninvasive characterization of fluid-preserved specimens and their conservation status.
• To provide detailed chemical insights into preservation fluids and specimen-fluid interactions.

Main Methods:

• Utilized handheld spatially offset Raman spectroscopy (SORS) for in situ analysis of sealed wet collection items.
• Characterized major and minor components in preservation fluids, including lipids, protein fragments, and fixation products.
• Directly probed specimen composition without opening containers.

Main Results:

• SORS provided detailed chemical information on minor dissolved components and organic deposits within containers.
• Demonstrated the capability to assess fluid degradation, leakage, and specimen-fluid interactions.
• Successfully performed in situ measurements on sealed specimens, showcasing versatility.

Conclusions:

• SORS is a robust and versatile tool for comprehensive monitoring of wet collection status under museum conditions.
• Offers actionable insights into degradation processes and long-term collection integrity for curators.
• Enables noninvasive, detailed chemical characterization beyond basic constituent analysis.