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Spectrophotometry Facility

The Instrument Center has capabilities in a range of methods for spectrophotometry.

Fourier transform infrared (FTIR) spectrophotometry

Absorption of light in the 4000-400 wavenumber range is used to identify functional groups in molecules due to peaks occurring at characteristic frequencies.

Available instrumentation

  • Perkin Elmer 1760 FTIR spectrometer with the following accessories:
  • Spectra-Tech IR Plan microscope
  • Diffuse reflectance (DRIFT)
  • Horizontal attenuated total reflectance (HATR)
  • Multiple internal reflection (MIR) accessories
  • Detectors include both TGS and MCT
  • Zeiss Stemi 2000 stereomicroscope
  • Mattson Alpha Centauri Infrared Spectrometer

Capabilities

  • Quantitative analysis of known compounds in mixtures
  • Aid in determining structures of unknowns
  • IR microscopy
  • Identification of contaminants
  • Examination of multilayered laminates
  • Examination of coatings and films
  • Analysis of surface defects
  • Diffuse reflectance FTIR
  • Analysis of powders directly without making pellets
  • Horizontal ATR
  • Characterization of liquids, pastes or compressible powders, films or solids
  • Multiple internal reflection

Ultraviolet/visible (UV/Vis) spectrophotometry

Available instrumentation

Hewlett Packard 8452A Diode Array Spectrophotometer with magnetic stirrer, temperature control, data station. Spectral range = 190 – 820 nm at a maximum acquisition rate of 1 scan/0.1 sec.

Applications

  • Characterization of electronic properties of molecular and materials samples
  • General survey scans for qualitative analysis
  • Reaction kinetics using single to full wavelength range
  • Quantitative analysis of single or multiple components

Fluorescence spectroscopy

Fluorescence is the emission of electromagnetic radiation from an excited singlet state of a molecule to its corresponding ground singlet state. Fluorescence spectroscopy exhibits superb detection limits (to “single molecule levels” with a laser and proper optics) and provides information about the photophysics of the emitting species and/or the local environment surrounding the fluorescence center.

Available instrumentation

  • SLM 8100 spectrofluorometer with a wavelength range of 200-900 nm. The spectral resolution is adjustable from 0.25-32 nm. The system is capable of the following basic experiments:
  • Steady-state excitation and emission scanning as well as synchronous scanning
  • Fixed wavelength intensity acquisitions
  • Time-dependent intensity data for ms or slower kinetic experiments
  • Steady-state polarization/anisotropy experiments

Applications

  • Determination of fluorophore concentration
  • Screening for polycyclic aromatic hydrocarbons
  • Determination of excitation and emission profiles for fluorophores and phosphors
  • Determination of quantum yields
  • Probing the local environment surrounding the fluorophore (pH, dipolarity, mobility)
  • Characterization of vesicles, protein-protein interactions, host-guest/protein-ligand binding studies and binding equilibria
  • Characterization of Forster energy transfer
  • Polarization immunoassays
  • Measurement of enzyme kinetics
  • Solid-surface luminescence