Page 324 - Tandem Techniques

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but there appears no reason why this should not be possible. The main advantage of the device appears
to be that proteins can be collected with the minimum amount of structural alteration, and thus true
spectra of the protein can be obtained.

The Series 100 LC-Transform TM LC/FTIR Interface

One of the few LC/FTIR interfaces that are commercially available is that provided Lab Connections
Inc., the design of which is based on, or similar to, the apparatus described previously by Lang and
Griffiths. The instrument is a transport type of interface, but uses a monocrystalline germanium disk as
the carrier. The germanium disk is transparent to IR light over the range of wavelengths that provide
molecular structure information. A section of the disk is shown in Figure 8.14.

Figure 8.14
Section of the Germanium Disk Transport System
Courtesy of Lab Connections Inc.

The disk is about 1.5 mm thick and the lower surface is coated with aluminum to reflect any IR light
that passes through it. The passage of the IR light beam, to and from the optical unit, is illustrated in
Figure 8.14. Germanium has a high transmittance to light in the infrared range (6000 to 500 cm- ) and
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the disk is arranged so that the light beam passes through the deposited solute to the reflective backing,
and then back