Article

Simple, non-moving modulation interface for comprehensive two-dimensional gas chromatography

Department of Analytical Chemistry and Applied Spectroscopy, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, Netherlands
Journal of Chromatography A (Impact Factor: 4.26). 07/2001; 919(1):127-132. DOI: 10.1016/S0021-9673(01)00785-3

ABSTRACT A simple, non-moving dual-stage CO2 jet modulator is described, which cools two short sections of the front end of the second-dimension column of a comprehensive two-dimensional gas chromatograph. A stream of expanding CO2 is sprayed directly onto this capillary column to trap small fractions eluting from the first-dimension column. Remobilization of the trapped analytes is performed by direct heating by the GC oven air. Installation, maintenance and control of the modulator is simple. Focusing and remobilization of the fractions is a very efficient process, as the bandwidths of the re-injected pulses are less than 10 ms. As a result, alkane peaks eluting from the second-dimension column have peakwidths at the baseline of only 120 ms.

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    • "The LMCS (Longitudinally Modulation Cryogenic System) generates modulation by moving back and forth a cryogenic CO 2 spray along the head of the second column (Marriott and Kinghorn, 1997; Kinghorn and Marriott, 2000). The dual-jets CO 2 modulator enables modulation by turning on and off two sprays of CO 2 applied on the column (Beens et al., 2001). The cryogenic approach is devoted to a wider boiling point range of volatile compounds but liquid nitrogen should be preferred to CO 2 for trapping of very volatile solutes. "
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