MCI Project Summaries 2008 - Smithsonian Institution

MCI 6240 Imitation-Metal Paint Study
MCI Staff: Carol A. Grissom, Mel J. Wachowiak, Judy Watson
Metal-flake containing paints (especially the imitation-bronze paints) from the latter half
of the 19 th century through the early 20 th century were technically examined with conventional
polarized light microscopy and SEM-EDS to better understand the range of imitation-metal
paints used during this period as well as their deterioration. A paper on this project has been
submitted to a conference.
MCI 6244 Sourcing Slate in the Far Northeast: An Examination of Prehistoric
Exchange Systems in Newfoundland and Labrador
MCI Staff: Chris Wolff, R. Jeff Speakman, Nicole C. Little, Judy Watson
The study focused on the characterization of slate recovered from Maritime Archaic sites
and known quarries in Newfoundland and Labrador using a variety of geochemical and
mineralogical techniques, all of which can be conducted at the MCI. This included X-ray
diffraction (XRD) analyses to determine the principal minerals present, X-ray fluorescence
spectroscopy (XRF) to determine the total chemical composition, and scanning electron
microscopy with X-ray microanalysis (SEM-EDS) to determine the chemical composition of
individual minerals. The study also included macroscopic and microscopic petrographic analyses
to characterize the physical properties (e.g., inclusions, texture, and color) of the slate varieties.
These resulting data then was used to assess the diachronic distribution of specific slate varieties
through the Maritime Archaic period, and to map out social connections and/or seasonal
migration routes by various regional groups.
MCI 6245 Development of SERS Active Vapor Sensors for Detection of Volatile
Museum Contaminants
MCI Staff: Odile Madden, Ron H. Cunningham, Nicole C. Little, Judy Watson
The project is to develop surface enhanced Raman spectroscopic (SERS) substrates that
absorb, concentrate and amplify the Raman signal of organic compounds that are present in air as
gases or vapors. In the museum context, such vapor sensors could be applied to the detection of
volatile pesticides, acids, and other organic compounds such as plasticizers that emanate from
museum collections as a result of artifact degradation or past applied treatments.
Several conservation departments have requested that MCI undertake analysis of volatile
compounds that may be toxic to human health or deleterious to susceptible artifacts located in
the vicinity. In particular, detection and identification of pesticide residues on museum artifacts
is a serious and urgent challenge. Organic artifact materials, such as wood, animal hide, basketry,
textiles, paper, horn and bone, have traditionally been treated with pesticides in order to eradicate
and prevent infestation by insects, rodents, and mold. A broad range of chemicals have been
used; these include salts of mercury and arsenic; DDT and other organochlorines;
organophosphates; carbamates; strychnine; naphthalene; paradichlorbenzene; and ethylene oxide,
among others. These poisonous substances can persist for years in the controlled environment of
a museum storeroom and present a poisoning risk to people who come in contact with the
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