Dating silk by capillary electrophoresis mass spectrometry

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moini's team used mass spectrometry to calculate the ratio of d- to l-forms, and thereby to determine the age of silk textiles. order of the world war medal with its colorful ribbon is one of many artifacts in the collections of the smithsonian’s national air and space museum that contain silk. archaeologists and forensic anthropologists have used this process for decades to date bone, shells and teeth, but the techniques used required sizeable samples, which for precious silk objects are almost impossible to obtain., which is composed of intertwining strands of protein extruded by silk worms, has been used as a textile for some 2,500 years. measuring this ever-changing ratio between left-handed and right-handed (d) amino acids can be used as a scientific clock by which a silk’s age can be estimated. the researchers demonstrated the test, called “ce-ms,” on sheridan’s flag, a fontainebleu tapestry, ancient silks from china and other old samples from masterpieces in museums around the world.

New technique for dating silk developed by Smithsonian

title:  using stable isotope mass spectrometry to establish the provenance of human remains from antebellum united states. measuring this ever changing ratio between the two types of amino acids can reveal the age of a silk sample..Because carbon-14 dating methods require so much material–a few milligrams--the new technique is a "promising" solution for dating silk, comments maarten van bommel, a senior scientist at the cultural heritage agency of the netherlands. he would like to see the new method validated on more silk samples.. moini has developed a novel handheld analytical technique called ultrafast capillary electrophoresis mass spectrometry (ce-ms) that uses short, narrow capillaries, with separation potentials in excess of 1000v/cm, to deliver samples into the mass spectrometer. during this research, specimens of silk with known ages were analyzed for their isomer ratios and a calibration curve was created correlating age to ratio.

Dating Silk By Capillary Electrophoresis Mass Spectrometry

Museum Conservation Institute REU 2012 Projects

Museum Conservation Institute Conservation & Technical Studies

for strand no fabric can compare to the luxurious feel, luminosity and sheen of pure silk. the d/l ratio provides a highly accurate measure of a silk object’s age, age to within 50-100 years and whether it is deteriorating and needs conservation work. technique requires a silk sample that is far smaller than what is consumed during carbon-14 dating, the only other scientific method that can date silk, explains mehdi moini, a research scientist at the smithsonian institution's museum conservation institute. japanese artwork, “pair of cranes on branch,” was made from ink and color painted on silk.  this calibration curve can now be used to indentify unknown ages of other silk specimens..; a man’s suit coat (1740) from the museum of the city of new york; and  a silk mexican war flag (1845-1846) from the smithsonian’s national museum of american history.

New technique for dating silk developed by Smithsonian

First practical scientific test to date and authenticate priceless silk

those items included new silk fibers; a silk textile from the warring states period, china (475-221 b. archaeologists had used the d/l approach to date ancient teeth and bone, but moini’s team simplified it and adapted it for silk. develop the new technique, the smithsonian team took a close look at aspartic acid residues in the silk protein. until now, however, there has been no practical scientific way to tell whether a silk tapestry is a well-preserved example from the fontainebleu series from the 1540s or a copy made just last week.  using an in-house developed technique combining capillary electrophoresis and mass spectrometry, one can separate isomers of amino acids and compare their relative ratio..; and silk artifacts from china's warring states period, which occurred between 475 and 221 b.

Silk Artworks Reveal Their Age | Latest News | Chemical

as time goes by the abundance of the l-amino acids used in the creation of the silk protein decreases while the abundance of d-amino acids associated with the silk’s deterioration, increases.  further preliminary research included identifying common contaminants of silk, applying the technique to bone collagen, and studying factors which affect the conversion between isomers., the scientists write, dating silk has been largely been a speculative endeavor that has mostly relied on the historical knowledge of a silk piece, as well as its physical and chemical characteristics. it is one of hundreds of artworks containing silk fibers in the collections of the smithsonian’s freer and sackler galleries. artworks reveal their age:Dating silk with some fluffy (but good) science. practical scientific test to date and authenticate priceless silk masterpieces.

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    practical scientific test to date and authenticate priceless silk masterpieces.  it is driven by advances in molecular separation and mass spectrometry technology over the past twenty years. solution is a new test that tracks time-related deterioration the amino acid building blocks in silk protein..) from the metropolitan museum of art in new york city; a silk tapestry (1540s) from the fontainebleau series, kunsthistorisches museum, vienna, austria; a silk textile from istanbul (1551-1599) from the textile museum, washington, d. new mass-spectrometry method will allow museum scientists to date ancient silks from just the fluff that falls off these priceless textiles (anal. new method uses the natural deterioration of the silk’s amino acids, a process known as racemization, to determine its age.
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    smithsonian museum conservation institute team used fiber samples taken from a series of well-dated silk artifacts to create a chart of left-hand and right-handed amino-acid calibration ratios against which other silks fabrics can be dated.” the new technique takes about 20 minutes, and requires the destruction of about 100 microgram of silk fiber, making it preferable over c14 (carbon 14) dating, which requires the destruction of so much material that it is prohibitive for most fine silk items. project focused on dating proteinaceous museum specimens using amino acid racemization mass spectrometry techniques. particular, she wonders whether textile contaminants or environmental conditions experienced by the silk affect racemization rates in a way that would undermine the accuracy of the dating technique. moini and colleagues at the smithsonian institution point out that for thousands of years, silk fibers, consisting of natural protein unwound from the cocoons of the silkworm, have been woven into not just garments, but wall hangings, tapestries, carpets and painted silk artworks. in many cases, scientists could not use the familiar carbon-14 dating process, because it involves taking samples of material large enough to cause visible damage to the silk object.

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