Ancient civilizations appear to have used sophisticated paint mixtures much earlier than previously known, according to new research conducted with use of high-energy x-rays. An international group of scientists analyzed 12 fragments from ancient Egyptian papyri with these devices, and found that both the red and black inks included lead compounds. This is evidence that the lead compounds were added for their fast-drying properties, not for pigmentation. While scientists have been aware that this practice was used by painters in 15th century Europe, this study indicates that ancient Egyptians employed it 1,400 years earlier.
The analysis of the paint was conducted using synchrotron radiation, or a thin bean of very high-intensity x-rays generated in a particle accelerator. The process is useful for analyzing art and other priceless artifacts, allowing scientists to image and analyze fine details.
Standards have long supported the technology used to make x-rays functional, reliable, and safe. ASTM E2809-13, Standard Guide for Using Scanning Electron Microscopy/X-Ray Spectrometry in Forensic Paint Examinations, is a standard guiding the use of scanning electron microscopy intended for use in forensic labs – a different application of paint analysis than that used by the scientists examining papyri. Forensic scientists may need to analyze a paint sample found at a crime scene to develop a link to a person, place, or object – for example, paint chips from a car at the scene of an accident. This standard was developed by ASTM International, a member and audited designator of the American National Standards Institute (ANSI).
X-rays can be used to analyze the composition of materials far beyond paint, including gasses and ceramics, woods and plant parts, oils and glues, and even teeth and bones. ISO 15470:2017, Surface chemical analysis - X-ray photoelectron spectroscopy - Description of selected instrumental performance parameters, is one standard that supports the use of x-rays for material analysis when a photoelectron spectrometer is used. Another standard that guides x-ray use in material analysis is ISO 16413:2020, Evaluation of thickness, density and interface width of thin films by X-ray reflectometry – Instrumental requirements, alignment and positioning, data collection, data analysis and reporting. These standards were developed by the International Organization for Standardization (ISO) Technical Committee (TC) 201, Surface Chemical Analysis. ISO 15470 was developed by TC 201/ subcommittee (SC) 7, Electron spectroscopies. ASTM is the ANSI-accredited U.S. Technical Advisory Group (TAG) Administrator to TC 201.
Ancient artifacts give us valuable information about the history of humankind, and their preservation is essential. Standards for museums help assure that these relics can be made available for people to see and learn from while still being preserved in their original condition. These are some of the many standards that support museum operations:
Read more about how x-rays helped scientists discover the use of lead compounds in paint by Ancient Egyptians on Wired.com: High-Energy X-Rays Reveal the Secrets of Ancient Egyptian Ink.