Panorama of chemistry laboratory

Instrumentation

Analytical Techniques

Analytical techniques in the Lasseter Clare group focus on non-destructive methods that characterize material properties and chemical composition. Some of the current technologies in the lab are:

X-Ray Fluorescence

  • Characteristic emitted X-rays are used for elemental identification of liquids and solids. X-ray fluorescence spectroscopy is ideally suited for elemental analysis due to it's non-destructive and non-invasive capabilities.
  • Characteristic X-rays are emitted by relaxation of electrons from higher to lower energy states
  • Each element has a discrete set of emitted x-ray energies that are characteristic of the atomic orbitals' energies
  • Peaks result from Kα/β/γ; Lα/β; Mα transitions

Electrochemical Techniques

  • Electrical and barrier property analysis of materials

Micro-Infrared Spectroscopy

  • Vibrational spectroscopy for the identification of chemical functional groups
  • Microsample for selective analysis
  • ~10-100μm spot size

Micro-Raman Spectroscopy

  • Sensitive scattering spectroscopy for the identification of chemical functional groups
  • Lasers of different wavelengths are routed through a microscope to enable acquisition of a Raman spectrum in the objectiveʼs field of view. Raman spectroscopy is ideally suited for either micro-sampling (using a needle probe to collect a small sample) or in situ methods (where no sampling is necessary). 

Infrared Reflectography

  • Black-and-white imaging method which measures infrared absorbance and produces a corresponding image of the object of study
  • Useful for pigment and material identification, particularly when coupled with visible light photography

Computed Tomography (CT) Scanner

  • Uses X-Rays to produce "slices" or images representing cross-sections or slices of an object. These can be compiled into 3D digital representations of an object
  • Variation in densities can be assigned colors or values, facilitating the non-invasive study of the interior of art objects
CT scan of an ammonite fossil reveals void spaces remaining from the chambers of the nautilus. The structure of the object can be examined from any angle and the high-resolution achievable allows for the study of small structures within.
Differences in density are revealed in this CT scan of a steel singing bowl. Welds can be seen, indicating the bowl was constructed from sheets of steel welded together to form the bowl shape.