Spectroscopy

The infrared and Raman spectroscopy section of the CAF is equipped with two Perkin-Elmer Spectrum 100 FTIR spectrometers, one of which is interfaced to a Perkin-Elmer Spotlight 400 FTIR imaging system, a Nicolet NXR 9650 FT-Raman spectrometer and a Renishaw inVia dispersive Raman microscope. The spectroscopy suite also includes a Varian Carey Eclipse Fluorescence Spectrophotometer and a Varian Carey 300 UV Spectrophotometer.

Infrared spectroscopy

Perkin-Elmer Spectrum 100 FTIR spectrometer

This is a simple-to-use, top-of-the range benchtop FTIR. It is normally set up with an ATR attachment allowing rapid recording of FTIR spectra from solids, solutions, creams, pastes tablets etc. The ‘Spectrum’ software is straightforward to use. The instrument includes Atmospheric Vapour Compensation (AVC) allowing peaks from water and carbon dioxide to be easily subtracted from the spectrum, and the wavenumber calibration of the instrument is carried out by means of an Absolute Virtual Instrument (AVI) system, giving a very high accuracy. Other accessories available with this instrument are a reaction monitoring probe and a variable temperature solution cell.

Perkin-Elmer Spotlight 400 Imaging System

A second Perkin-Elmer 100 FTIR spectrometer is interfaced to a Spotlight 400 Imaging System. This system combines high sensitivity and rapid imaging with ease of use. The ability to image rapidly large sample areas at high spatial resolution (down to 10 microns) allows the instrument to be used for a very wide range of applications, such as the study of biomaterials (tissue, bone, leaves etc.), studies of micromorphology in archaeological samples, studies of single crystals of chemical samples, and monitoring of counterfeiting in documents and banknotes. The Spotlight 400 can be used in the mid- and near-IR spectral ranges. A feature of the instrument available in the CAF is an ATR imaging accessory which improves the spatial resolution by a factor of four, down to three microns at 1000 cm^-1.

Specific features and benefits of this instrument are as follows:

• very high sensitivity providing high quality data down to the accepted diffraction limits;
• rapid-scan IR imaging;
• 6.25 µm, 25 µm and 50 µm pixel resolution to give flexibility in spatial resolution and imaging line;
• operation in mid-IR, near-IR or dual range to cover the full range of imaging applications in one instrument.

An ATR imaging accessory is available improving the spatial resolution by a factor of four, down to three microns at 1000 cm^-1.

Raman spectroscopy

A FT Raman spectrometer operating with a near infrared (1064 nm) laser source and a dispersive Raman microscope operating with lasers at 765, 633 and 532 nm are available.

Renishaw inVia Dispersive Raman Microscope

The Renishaw inVia Raman microscope is considered to be one of the most flexible instruments on the market. The instrument available in CAF is equipped with laser sources at 785, 633 and 532 nm allowing a wide range of samples to be studied and for problems of fluorescence or photolysis to be overcome. The instrument is fitted with a cooled UV near infrared enhanced CCD array detector, and a typical resolution better than 1 cm-1 is easily achievable. The instrument has a selection of different objectives including a water immersion lens for optical trapping or investigating living cells, and with magnifications between x5 and x100, allowing spatial resolution down to a micron, and confocal measurements with 2.5 micron depth resolution. Further accessories include an external fibre optic probe, and full polarisation control of incident and scattered light.

Thermonicolet NXR 9650 FTRaman spectrometer

This high-performance simple-to-use FT-Raman spectrometer is ideal for liquid and powder samples, where easy FT-Raman sampling can be carried out in standard glass vials or NMR tubes. Further accessories include cryo- and temperature-controlled cells (up to 180 °C), and full polarisation control of laser and scattered light, for Raman depolarisation measurements. The instrument has a 1064 nm near-infrared laser with operating power up to 2W, and the choice of two detectors, one InGaAs, and the other a high-sensitivity liquid nitrogen-cooled germanium detector. These features provide new sensitivity and speed in Raman detection, making the Thermo Scientific NXR 9650 best in class for FT-Raman spectroscopy.

Visible and fluorescence spectroscopy

Varian Cary 300 UV-Visible spectrometer

The Varian Cary 300 spectrophotometer is used worldwide for routine analysis and research. It covers the wavelength range 190-900 nm with a limiting resolution of 0.193 nm. The instrument has a number of accessories, including polarisers, and solid and variable temperature sample chambers.

Varian Eclipse Fluorescence spectrophotometer

The Varian Eclipse Fluorescence instrument incorporates the latest optical and electronic technology to provide excellent sensitivity and ease of use. The instrument covers the wavelength range 200-900 nm in excitation and emission, and is capable of fluorescence, phosphorescence and chemi/bio luminescence experiments. Accessories include a multi-cell temperature control unit (0-100 °C), a fibre optics dip probe for in situ measurement of samples in beakers or flasks, and a stopped flow system with rapid (8 ms) mixing, for fast kinetic experiments.