MCI Instrumentation: Supporting Smithsonian Science Proteomics, MS/MS, SEM,
ICP-MS, XRF, pXRF, micro-XRF, XRD, Raman, portable-Raman,
FTIR, Gas Chromatography, Stable Isotope Mass Spectrometry, Infrared
Imaging, Multi-Spectral Imaging, 3-D Scanning, Optical Microscopy,
3-D microscopy, Thermal
Analysis, Light Fading, Radiography,
Materials Aging |
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Analytical Technique |
Instrumentation |
Application(s) |
Proteomics |
Orbitrap Velos
|
Used
for the large-scale study of protein structure and function including
chemical characterization and quantitation of
biological and chemical samples. (available
at MCI in early 2011) |
Organic MS/MS |
Thermo LCQ-DUO
|
Instrument 1 has a Beckman
Coulter Capillary Electrophoresis (CE) front end and is used for biological
aging projects. Instrument 2 has a IonSense DART (Direct Analysis
Real Time) peripheral used for surface analysis of organic compounds. |
SEM Scanning Electron Microscopy, SEM-EDS SEM-Energy Dispersive Spectroscopy, SEM- µXRF SEM-micro X-ray Fluorescence
Spectrometer |
Hitachi S-3700N Variable Pressure Scanning
Electron Microscope w/Bruker EDS and IXRF fX series micro-XRF
|
Used
for low- and high-magnification imaging at variable pressure (<1–270 Pa).
The sample chamber can accommodate objects up to 30 cm in diameter and 8 cm
in height. This instrument is capable of imaging and analyzing intact objects
non-destructively, without the need to sample, embed, polish and coat as in
traditional SEM-EDS. The EDS and µXRF are used for inorganic elemental
mapping and analysis of samples. Depending on the nature and preparation of
the sample, EDS analyses can be qualitative or fully
quantitative, with limits of detection possible down to 0.5%; in some cases
detection limits of 10 ppm are achievable with the
µXRF. Figure: SEM-EDS elemental
map of oxygen (orange), carbon (green) and phosphorus (purple) in degraded
cellulose acetate. The crystals are enriched in phosphorus relative to the
surrounding area. |
TOF-ICP-MS Time-of Flight Inductively Coupled Plasma-Mass
Spectrometry LA-ICP-MS Laser Ablation Inductively Coupled Plasma-Mass
Spectrometry |
GBC Optimass
TOF-ICP-MS New Wave 266 nm laser ablation system |
Able
to measure most elements on the periodic table. ICP-MS is especially useful
for analysis of inorganic materials, such as metal alloys, glass, ceramics,
pigments, and minerals. Samples
can be introduced to the spectrometer as a solution or in solid form via
laser ablation, which is minimally invasive to the object. Detection
limits range from %-level to ppb or ppt range for
many elements. Figure: Laser Ablation craters
after the analysis of a glass bead. The total area impacted is ca. 0.08 mm
diameter. |
ED-XRF Energy Dispersive X-ray Fluorescence
Spectrometer |
|
Benchtop XRF instrument
used for non-destructive elemental analysis in the laboratory or in the
collection facilities. XRF is especially useful for identifying inorganic
compounds such as metal alloys, glass, ceramics and pigments. |
p-XRF Portable X-ray Fluorescence
Spectrometer (Two instruments available) |
Bruker Tracer III-V ED-XRF |
Portable
handheld XRF instrument used for non-destructive elemental analysis; p-XRF is
especially useful for identifying inorganic compounds, such as metal alloys, glass,
ceramics and pigments. Figure: Plot of zirconium
and strontium concentrations (ppm) for 2154
obsidian artifacts analyzed by portable XRF. Each cluster corresponds to a
specific geologic outcrop. |
micro-XRF |
Bruker ARTAX micro XRF
|
Micro-XRF
instrument used for non-destructive elemental analysis and generating high
resolution elemental maps Figure:
Elemental
map (ca. 40 x 15
mm) of chromium distribution in a lunar gabbro
meteorite. Warmer colors equal higher concentration, i.e., red is olivine. |
XRD X-ray Diffraction |
Rigaku D/MAX-RAPID XRD
|
Used for identification of crystalline structure in inorganic
materials; especially useful for pigments, minerals, and corrosion products. Figure: Typical XRD pattern for dolomite. |
Raman Spectroscopy: FT-Raman & Dispersive Raman |
Thermo Nicolet Almega XR Dispersive Raman Spectrometer
|
Raman
is used to provide qualitative and quantitative information on organic and
inorganic molecules in a given sample matrix. Raman is particularly useful
for examining polymers, monomers, and other modern materials found in
museums, as well as proteinaceous and keratinaceous materials, pigments, and some corrosion
products. Spectra
are very specific; chemical identifications can be performed by using search
algorithms in digital databases. Analyses
are non-destructive; little or no sample preparation is required. Fiber
optic lines can be used for analyses ‘outside of the box’. Figure: Typical Raman spectrum
for cellulose acetate. |
Thermo FT Raman |
||
Portable Raman |
B&W TEK MiniRam
II |
Portable
Raman system with a 10 cm-1 spectral resolution through the Raman shift range
of 175–3100 cm-1, with an integrated stabilized 785nm excitation laser. By
using the fibre-coupled sampling probe, users can
collect Raman spectra of solids or liquids in the field. |
FTIR Fourier Transform Infrared |
Thermo
Nicolet 6700 Fourier Transform Infrared Spectrometer with Centaurus
microscope and Golden Gate micro Attenuated Total Reflectance (ATR)
accessory. |
FTIR
used to produce a "fingerprint" spectrum of different chemical
compounds within objects. FTIR is useful for characterizing organic
molecules, such as coatings, adhesives, and paint binders, and some inorganic
molecules. Figure: Comparison of FTIR spectra. Top: a palmitic acid standard; Bottom: sample from an ethnographic
object. |
GC Gas Chromatography GC/MS Gas Chromatography Mass Spectrometry Py-GC/MS Pyrolysis Gas Chromatography
Mass Spectrometry HS-GC/MS Headspace Gas Chromatography Mass
Spectrometry |
Instrument
1-Agilent 6890N GC with Agilent 5975 quadrupole
mass spectrometer, CDS Pyroprobe 5150 pyrolyzer, & Agilent 7694E headspace sampler |
GC
and GC/MS are instrumental technique in which complex mixtures of chemicals
may be separated, identified and quantified. The technique first vaporizes
dissolved samples or derivatives (chemically modified samples), into gases
and then separates according to their volatility (and polarity). In MS each
gas is then bombarded with electrons so that ion fragments are formed. These
ions are separated and filtered according to the fragment masses and counted.
Interpretation of the resulting mass fragmentation patterns provides the
identification of the gases and ultimately the chemical makeup of the sample.
Py-GC/MS is used to
provide rapid analysis of solvent-insoluble samples, but is particularly
useful analysis of intractable and nonvolatile macromolecular complexes,
i.e., polymers, soils, sediments, and hair. Figure: Pyrogram of Flo-texx, a product used as a mounting medium in microscopy.
Large peak in the center is methyl methacrylate;
the large peak on the right is n-butyl methacrylate. |
Instrument 2-Agilent 5890 GC with ECD
and NPD |
||
IRMS Isotope Ratio Mass Spectrometry |
Instrument-1
Thermo Delta V Advantage with Conflo-IV Interface,
and Costech EA |
Used
for high-precision isotope ratio studies of carbon, nitrogen, oxygen,
hydrogen, and sulfur (C, N, O, H, and S). C,
N, O, H, and S naturally occur as two or more stable (non-radioactive) isotopes.
The stable isotope composition of organic and inorganic substances can be
used to trace the pathways and forms that these key elements take as they are
transferred and cycled within biological and geochemical systems.
Measurements of stable isotope ratios in soils and plant samples are used to
reconstruct past climates and vegetation, evaluate physiological responses of
wild and domesticated plants (and animals), characterize energy and material
transfers and transformations among plant, animal, and microbial components
of ecosystems, and understand atmosphere-biosphere interactions. Stable
isotopes record information on biological and physical processes operating
across space and time, and thus are useful in integrative studies that span
disciplines and levels of biological organization. Rapid and precise stable
isotope analysis of solid, liquid, and gaseous materials is fundamental to
many studies in physiology, ecology, hydrology, and earth and atmospheric
sciences. Figure: Chromatogram of
N2 and CO2 isotopes in an organic standard. http://si.edu/mci/irms/index.htm |
Instrument-2
Thermo Dual inlet Delta V Advantage with Conflo-IV
Interface, GasBench II with GC PAL autosampler, and Thermo TC/EA |
||
EA Element Analyzer |
Costech ECS 4010 CHNOS
Element Analyzer |
Can
be used as a stand-alone instrument to measure bulk carbon, nitrogen, oxygen,
hydrogen, and sulfur in a given sample, or as a
sampling system for IRMS that does not contaminate the sample with
atmospheric nitrogen and oxygen, especially working at very low
concentrations. |
Infrared Reflectography |
|
Non-destructive
technique used to examine paintings and artworks and detect hidden details
under the upper layers such as added paint, underdrawings,
and hidden signatures or watermarks. (Instrument purchase courtesy of Smithsonian Women’s Committee
Grant) http://si.edu/mci/ImagingStudio/Multispectral%20Imaging.html |
Multi-Spectral Imaging |
Surface Optics SOC710 Camera |
Used for imaging in the 400 to 1000 nanometer spectral range.
Lenses are interchangeable and the camera can be fixed to a tripod or to any
microscope for biological scanning. |
3-D Scanning |
Breuckmann GmbH triTOS-HE
structured light scanner |
Used
for high-resolution, digital, 3-dimensional documentation projects. By
viewing the data files with 3D graphic software, it is possible to view and
manipulate the 3D graphic models on a computer screen, make virtual
measurements, and create virtual lighting to best study the surfaces of the
object. The 3D data also can be used to make replicas in the positive or
negative at any scale in almost any material by computer numerical controlled
milling (CNC) or rapid prototyping.
Figure: 3-dimensional representation
of a 2nd century B.C.E. bronze torso recovered from the Vani site, Republic of Georgia. http://si.edu/mci/ImagingStudio/3D%20Scanning.html |
Optical Microscopy |
Multiple microscopes at MCI http://si.edu/mci/ImagingStudio/Microscopy.html |
Used to document, describe, analyze, and identify objects;
provides unique information about the structure and state of preservation of
objects and the identity of their component materials. |
3-D Microscopy |
|
Used for 3-dimensional imaging analysis; provides unique
information about the structure and state of preservation of objects and the
identity of their component materials. (Instrument purchase courtesy of Smithsonian Women’s Committee
Grant) http://si.edu/mci/ImagingStudio/Microscopy.html |
DSC Differential Scanning Calorimetry DTA Differential Thermal Analysis TGA Thermo-Gravimetric Analysis |
|
DSC
and DTA are used to study phase transitions, such glass transition melts and
other thermal transitions. TGA
is used to examine the characteristics of materials such as polymers, to determine degradation
temperatures, absorbed moisture content of materials, the level of inorganic
and organic components in materials, decomposition points of explosives, and solvent residues. |
Micro-Scale Color
Fading Tester |
|
Used to determine light-fastness data for museum objects. The device consists of a reflectance spectrophotometer coupled
to an accelerated light fading micro-tester. The instrument uses fiber optics
for delivering light to the sample. Two advantages of this technique are small
spot size (< 0.4 mm) and short testing time (1-2 minutes). |
Digital Radiography |
GE Inspection Technologies Computed Radiography Scanner—Pegasus CR 50P Figure: Digital Radiograph
of a Nautilus shell. |
Used for the structural examination of art and
artifacts. For art works, it helps to reveal losses, replacements, and methods
of construction that may not be visible to the naked eye. Figure: Conventional film
radiograph of an early NASA training suit. |
Weather-ometer |
Atlas Ci4000 Xenon Weather-Ometer
|
The ci4000 is calibrated to run samples at museum conditions of temperature and relative humidity while exposing samples to accelerated light conditions, in order to assess the likelihood of degradation and deterioration during extended periods of museum gallery display. Other more extreme temperatures and humidity conditions can also be created and maintained; exposure to Ultra violet light or to infra red heating can be included or excluded. Particularly useful to gauge the length of gallery life for organic materials sensitive to light: natural dyes, plastic films, textile fibers, papers, feathers, leathers.
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