MCI Project Summaries 2008 - Smithsonian Institution

MCI 6110.1 Red-Slipped Maya Pottery
MCI Staff: Nicole Little, R. Jeff Speakman, Ron H. Cunningham
In order to better understand the mechanics behind pottery manufacture in northwest
Belize, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to
determine the chemical composition of slips and pigments from pottery samples previously
characterized by neutron activation analysis (INAA). Samples without extensive surface erosion
were analyzed in the hopes that patterns similar to previous research would be detectable in
surface treatments. Because slips and pigments do not have the same inherent problems as paste
(i.e., heterogeneity due to temper), LA-ICP-MS is the ideal technique for the compositional
analysis of surface treatments on pottery, and has shown to be successful in the chemical
characterization of ceramic pigments. Examination of the black slips and pigments yielded
significant differences in the raw materials used in their manufacture.
MCI 6133 Naturally Aging Conservation Polymers Spectral Reference Collection
MCI Staff: R. Jeff Speakman, Odile Madden, Jennifer Giaccai, Nadia Jimenez-Cano, Amber
Davis, Technical Studies Group
The 50 thermoplastic resins sold in The ResinKit were analyzed to form the basis of
spectral libraries for the FTIR and Raman. The ResinKit is published and distributed by
ResinKit and the Plastics Group of America as a test kit for identifying commercial standard
resins. The commercial resins include acetal resin, acrylic, acrylonitrile-butadiene-styrene (ABS,
multiple types), cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate,
ethylene vinyl acetate, ionomer, modified acrylic, nylon (multiple types), phenylene oxide,
polyallomer, polyaryl-ether, polybutylene, polycarbonate, polymethyl pentene, polyphenylene
sulfide, polyester elastomer, polyethylene (three densities), polypropylene (multiple types),
polystyrene (multiple types), polysulfone, polyvinyl chloride (PVC, flexible and rigid), styrene
acrylonitrile (SAN), styrene butadiene, styrenic terpolymer, synthetic elastomer (styrene-block
co-polymer), thermoplastic polyester (PBT), thermoplastic rubber, and urethane elastomer
(polyester).
The resins were analyzed by ATR-FTIR, the spectra saved in an archival format, and the
spectra imported into a searchable library for future FTIR searches. The IR spectra will be
submitted to the IRUG library so they will be available for searching by other museums and
conservation laboratories. The resins were also analyzed by dispersive Raman (532 nm), the
non-fluorescent spectra saved in an archival format, and both baseline corrected and nonbaseline
corrected spectra were imported into a searchable library using GRAMS Spectral ID for
future Raman searches.
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