Fall 2019 - Chemical Analysis Class Projects

Follow

• 

  Dye Compound Identification of an Innominate Textile Using Gas Chromatography-Mass Spectrometry

  Dexter L. Cox

  The art of coloring textiles emerged during the Stone Age with some artifacts dating as far back as 6,000 years ago.1

  Until the unintentional discovery of the first synthetic dye mauveine by William Henry Perkin in 1856, the majority of natural dyes were derived from plant, animal, and mineral sources.2

  Without proper conservation of an historical artifact, important details can be lost and prevent future research from being successful.

• 

  Mapping the Exterior of a Mastodon Tusk using UV-Vis Diffuse Reflectance

  Teresa Feldman

  The 12-foot, 600-pound mastodon tusk was discovered in Hampton, Iowa, in the 1930s by a man digging in the gravel. It was the largest discovered mastodon tusk until the 1970s. The tusk was donated to UNI in 1933, under Dr. Cable, and put on display at the UNI Museum in the 1960s. Over the years, there have been many efforts to conserve the tusk, but it has still sustained breakage and water damage. It has also been subject to inadvertent degradation from some of the previous conservation efforts.

  The purpose of the research conducted was to create a spectral map of the lacquers on the mastodon tusk at the UNI Museum. To accomplish this, a spectroradiometer with a diffuse reflectance tip was used to non-destructively collect UV-Vis spectra. In order to create a coordinate system for the mapping, a grid map was made for the tusk. Creating a UV-Vis map of the lacquers on the tip of the tusk will allow conservationists at the UNI museum a better understanding on how to proceed in their preservation of the tusk.

• 

  Investigation of Composition and Degradation in Gold Fibers from UNI Museum Textile Collection Using SEM/EDX

  Anna Martínez

  Scanning electron microscopy (SEM) and energy dispersive x ray spectroscopy (EDX) were utilized to determine the composition and degradation of gold fibers retrieved from textiles belonging to the UNI Museum textile collection. SEM provided magnified images depicting current state of fiber samples but was limited to determining condition of artifact as a whole. This investigation also yielded sample information of metallic elements present within the fibers such as gold, aluminum, and iron which were detected using EDX. Background

• 

  Fluorescence Mapping of Materials on Mammut Americanum

  Shaylah Peyton McCool and

  Mammut Americanum , more commonly known as the American Mastodon, is an extinct species found throughout North and Central America. Dated from either the Aftonian or Yarmouth age (120,000 to 200,000 B.C.E.), a 12 foot, 600 pound tusk of a mastodon was discovered in Hampton, Iowa in the 1930’s.

  In 1933, it was brought to the University of Northern Iowa for comprehensive research and preservation. The tusk was covered in unknown materials such as varnish, spackle, lacquer, and shellac in an attempt to preserve it before putting it on display in the UNI Museum in the 1960’s. Currently, the tusk is in two pieces, the smaller of which was the subject of this research.

  Fluorescence mapping of the materials on the Mastodon tusk is a necessary study as the lacquers hold the key to determining the future preservation methods required by the tusk.

• 

  Differentiation Between Mastodon Tusk Fragments And Plaster Using UV VIS Spectroscopy

  Bailey Miller

  The Mastodon tusk at the University of Northern Iowa provides students and faculty a unique challenge in research and conservation

  Determining the chemical composite of the tusk is difficult due to the work done on it since its discovery

  The use of UV VIS spectroscopy can be used to differentiate between tusk and plaster fragments

• 

  Identification of Dye Compounds in Chinese Artifacts by GC MS

  Pratima Raut

  UNI Museum homes wide variety of textile artworks.
  Many of them have historical significance. Two of them are UNIM 2005.2.24 (Tapestry) and UNIM1986.14.1985.1.124 (Hanging)

  Figure 1: UNIM 2005.2.24 (Tapestry)
  Rectangular Textile
  Dimension: 36cm × 69cm
  Dark blue silk embroidery of an old bearded man believed to be Chinese god, Shou Hsing
  Contrasting floral designed 1'' border
  “Made in China” stamp on the plain cotton fabric back

  Figure 2: UNIM 1986.14.1985.1.124 (Hanging)
  Silk fabric
  Dimension 158cm × 74cm
  Dimension: 36cm × 69cm
  Depiction of an elderly man like the one in Chinese folklore about prosperity
  Assumed to be of Chinese origin

• 

  NIR Mapping of the Mastodon Tusk Layers

  Carli Jo Russenberger

  This tusk was unearthed in September of 1933 in the town of Hampton, Iowa. About two feet from the proximal end, the tip broke upon extrication. In order to preserve this archaeological finding, many layers of lacquers, plasters, and varnishes were applied. 3 The layers of preservation are not well identified, as well as the timing of application.

  By using the Near Infrared (NIR) technique, infrared light is applied to the tusk and wavelengths are absorbed. The absorbances can help determine the functional groups of the restoration materials in the NIR range of 4,000 to 10,000 wavenumbers.

  The objective of the experiment is to provide guidance towards the identification of preservation techniques. By identifying the compounds, a more accurate timeline of preservation application can someday be composed.

• 

  Fiber-Optic Spectroscopy of Mandarin Square Textile Artifacts

  Joseph Leonard Tibbs

  Mandarin Squares were officially used from the Ming Dynasty (1391 AD) until the end of the Qing Dynasty (1912), though the tradition dates back even further

  These badges were instruments of politics and courtly etiquette, and the animal subject denoted rank and position

  Design subject to artistic movements as tastes changed

  Common elements include symbolism, good luck charms, flight/motion, mystical beasts (below)

  Traditionally worn as two panels on either side of a riding jacket, therefore split by a seam in the middle (see right)

  Above: Data Collection using handheld IR Fiber Optic probe Below: A sample page from the Kusakizome book

  Portrait of a Young Official (artist unknown, public domain)

  UNI 2000.10.0002 (“Dim”) UNI 2000.10.0003 (“Golden”)

  Traditional textile production in Japan included weaving, metallic thread coating, and dyeing using naturally-occurring minerals and plant products (Kusakizome)

  Dyes extracted by drying, grinding, boiling, fermenting, etc.

  Fabrics were soaked, and the dye fixed with lye, mineral mordants; over time, further chemical reactions could fade or change the color of the threads

  Most techniques to determine dye content in artifacts require destructive methods (such as GC-MS or Surface- Enhanced Raman Spectroscopy)

  However, non-destructive spectral analyses are possible if a suitable library of similar artifacts can be used for reference

  An analysis of the visible reflectance typically involves comparison of inflection points

  NIR has shown the ability to distinguish thread types