The Art of Dating Silk Textiles
A new mass spectrometry method will allow museum scientists to date ancient silks from samples that are far smaller than what is consumed during carbon-14 dating, the only other method that can date silk.
Mehdi Moini, a research scientist at the Smithsonian Institution’s Museum Conservation Institute (Suitland, Maryland), in collaboration with colleagues Kathryn Klauenberg and Mary Ballard, has developed a new mass spectrometry method that will allow museum scientists to date ancient silks from samples that are far smaller than what is consumed during carbon-14 dating, the only other method that can date silk.
To develop the technique, the Smithsonian team looked closely at aspartic acid residues in the silk protein extruded by silk worms. Over decades, these aspartic acid residues can turn into their mirror images, switching from the L-form to the D-form in a process called racemization. Moini’s team used mass spectrometry to calculate the ratio of D- to L-forms, and to thereby determine the age of silk textiles. They performed the analysis on 100 μg samples and smaller.
The researchers evaluated their technique on samples that included fresh silk from 2010; American civil war flags; a man’s silk suit from the 1700s; Turkish tapestries from the late 1500s; Egyptian silk yarns from 993 A.D.; and silk artifacts from China’s Warring States period, which occurred between 475 and 221 B.C.
A Life Measured in Peaks: Honoring Alan George Marshall (1944–2025)
June 18th 2025A pioneer of FT-ICR Mass Spectrometry, Alan G. Marshall (1944–2025), is best known for co-inventing Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), a transformative technique that enabled ultrahigh-resolution analysis of complex mixtures. Over a career spanning more than five decades at institutions like the University of British Columbia, The Ohio State University, and Florida State University, he published over 650 peer-reviewed papers and mentored more than 150 scientists. Marshall’s work profoundly impacted fields ranging from astrobiology to petroleomics and earned him numerous prestigious awards and fellowships. Revered for his intellect, mentorship, and dedication to science, he leaves behind a legacy that continues to shape modern mass spectrometry.
