Page 332 - Multidimensional Chromatography

322 Multidimensional Chromatography

Figure 12.15 Chromatographic analysis of styrene and its impurities: (a) precolumn chro-
matogram (the compound represented by the shaded peak is solvent flushed prior to transfer to
the second column); (b) main column chromatogram with cryotrapping. Conditions: DCS,
two columns and two ovens: CTS, columns, Ultra-2 (25 m 0.32 mm i.d., 0.52 m d.f.) and
DB-WAX (30 m 0.32 mm i.d., 0.25 m d f ). Reprinted with permission from Ref. (20).

The system used to carry out such an analysis is shown in Figure 12.16 with
the schematic diagrams of the dual-column switching (DCS) and multi-column
switching (MCS) modules being presented in Figure 12.17. The solvent flush via the
splitline is carried out when the MFC3 valve is open (Figure 12.17 (b)).

Figure 12.16 Schematic diagrams of the applied system involving cryotrapping, consisting
of a manual or automated injector (1), a temperature-programmable cold-injection system
with septumless sampling head (2), a gas chromatograph (3) configured with an FID monitor,
column-switching-device (4) and MCS or DCS pneumatics, connected via a heated transfer
line with an included cryotrap (5) to a second gas chromatograph (6) with a mass-selective
detector (7) (MCS, multi-column switching; DCS, dual-column switching). Reprinted with
permission from Ref. (20).