Revealing sassanid dyeing practices through synchrotron FTIR

Area of Science:

• Archaeological science
• Materials science
• Organic chemistry

Background:

• Textiles from the Chehrabad salt mine offer insights into Sassanid period (220-390 A.D.) material culture.
• Understanding ancient dyeing technologies is crucial for textile conservation and historical reconstruction.

Purpose of the Study:

• To identify natural dyes used in Sassanid wool textiles from Iran.
• To investigate dye-wool interactions and understand historical dyeing processes.
• To evaluate synchrotron-based FTIR microspectroscopy for non-destructive analysis of archaeological textiles.

Main Methods:

• Synchrotron-based Fourier-transform infrared (FTIR) microspectroscopy was employed for high-resolution chemical analysis.
• Principal component analysis (PCA) was used to process spectral data and identify dye components.
• Non-destructive spectral analysis was performed on wool textile samples.

Main Results:

• Identification of key natural dyes: indigotin (blue), tannic acid (brown), quercetin and apigenin (yellow), and alizarin and carminic acid (red).
• Absence of luteolin suggests the use of alternative native yellow dye sources.
• Evidence of dye-wool lipid interactions was observed in the Amide and lipid spectral regions.

Conclusions:

• Synchrotron FTIR microspectroscopy is a powerful non-destructive technique for analyzing natural dyes in archaeological textiles.
• The findings provide valuable insights into Sassanid dyeing technologies and regional dye use.
• The study highlights the potential for identifying unique or native dye sources in historical textiles.