Page 313 - Tandem Techniques

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The column eluent was mixed with nitrogen under pressure in a high pressure mixing T. The nitrogen-
eluent mixture was directed to the deposition surface through a syringe needle, fitted to the other port of
the high-pressure T. The syringe needle itself was situated inside another nozzle, through which heated
nitrogen was flowing. This arrangement warmed the eluent-nitrogen mixture, and thus increase the
evaporation rate, and also heated the receptor plate, which helped to remove the last residues of solvent.
The simple arrangement allowed the system to be employed with aqueous solvent mixtures and, at the
same time, significantly increased the overall sensitivity of the apparatus. The sensitivity of the
modified interface is demonstrated in Figure 8.5.

Figure 8.5
Results from the Modified LC/FTIR Interface
Demonstrating the Overall Sensitivity of the Tandem Instrument
Reprinted with permission from J. J. Gagel and K. Bieman, Anal.
''Chem.. 59(9)(1987)1267, Copyright 1987 American Chemical Society