Page 320 - Tandem Techniques
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The column conduit was a fused capillary tube, 40 cm long, 50 µm I.D which was connected, via a
suitable union, to a stainless steel needle, 100 µm I.D and 475 µm O.D. In the spray unit, a nitrogen
flow that could be heated up to 200°C, passed through a concentric outside tube, 600 or 900 µm I.D.
This system evaporated the solvent and deposited a solid sample onto the transport medium. The length
of inner tube that projected beyond the nitrogen sheath, and the distance between the end of the
deposition jet and the transport medium surface, were adjustable. The model compounds used were
fluoranthene, pyrene, benzo [a]anthracene and benzo[k]fluoranthene. A separation of these compounds
is shown in Figure 8.10 monitored directly by fluorescence detection and by scanning the transport
medium by densitometry.
Figure 8.10
Chromatograms of the Test Mixture Taken On-line by a
Fluorescence Detector and Off-line by Densitometry.
