Page 331 - Tandem Techniques

Page 315

It is clear that the performance of the commercially available instruments has now been much
improved, and it is likely that the technique will become far more popular in the future. A photograph
of the IOOLC-Transform LC/FTIR Interface fabricated by Lab Connections Inc. is shown in Figure
TM
8.20.

The obvious alternative to a transport interface is the in-line flow-through cell, and in 1983, Brown and
Taylor [17] introduced a micro IR cell, 3.2 µl in volume, that fitted directly into the IR spectrometer.
This arrangement constituted a true in-line LC/IR combination. They employed a small-bore column,
and claimed an overall increase in mass sensitivity of about 20 orders of magnitude, relative to the
standard 4.6 mm I.D. column. They employed an FT/IR spectrometer, but the actual sensitivity
improvement was obscured by the fact that the column length of the small bore column, was
significantly different from that of the standard column. As a result, the actual sensitivity improvement,
in terms of minimum sample mass that would provide an acceptable spectrum, could not be accurately
calculated. A simple cell for directly interfacing an LC microbore column to an FTIR spectrometer was
described by Johnson and Taylor [18].

Figure 8.21
Zero Dead Volume Micro IR Cell