Page 47 - Multidimensional Chromatography

Coupled HPLC with HRGC 37

Figure 2.16 Chromatograms of a pentane extract of a water sample containing 200 ppb of a
naphtha fraction: (a) sample extracted by using a continuous flow system, where a pressurized
bottle was employed as the sample-delivery system; (b) batch-extracted sample. Reprinted
from Journal of Chromatography, A 330, J. Roeraade, ‘Automated monitoring of organic trace
components in water. I. Continuous flow extraction together with on-line capillary gas chro-
matography’, pp. 263–274, copyrigth 1985, with permission from Elsevier Science.

such a system with an atomic emission detector (AED) for the analysis of nitrogen-
chlorine- and sulfur-containing pesticides in aqueous samples (39), as shown in
Figure 2.19.

2.5.3 OPEN TUBULAR TRAPPING

The analysis of organic compounds from aqueous samples is also possible by using
open tubular trapping (OTT) columns (13, 40–42). The extraction step involves
sorption of the analytes from water (40) into the stationary phase of an open tube
(5 m 0.53 mm id) with a film of CP-Sil-5CB (5 m film thick). Removal of water
is achieved by purging the trap with nitrogen, and desorption of the analytes with an
organic solvent (75 l). Solvent elimination prior to transfer to the GC column is
carried out by using a PTV injector and a multidimensional system (Figure 2.20).