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

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 co mprehensive two-dimensional gas chromatograph. A stream of expanding CO2 is sprayed directly onto this capillary column to trap small fractions elutin g from the first-dimension column. Remobilization of the trapped analytes i s 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-injecte d pulses are less than 10 ms. As a result, alkane peaks eluting from the se cond-dimension column have peakwidths at the baseline of only 120 ms. (C) 2 001 Elsevier Science B.V. All rights reserved.