GCxGC Flow Modulation Solution

Simplified Modulation through Quasi-Stop-Flow

Single-dimension GC is a powerful analytical technique, but it can have limitations when it comes to the analysis of complex mixtures and matrices. Comprehensive two-dimensional GC, or GCxGC, expands separation capabilities by adding a second, orthogonal column in series to the first column; however, this configuration can be expensive to implement and requires highly trained instrument operators.

ARC’s solution takes advantage of quasi-stop-flow modulation to make GCxGC an attainable configuration for any analytical laboratory. It involves continually sampling the effluent from the first column and re-injecting it onto a second, smaller column with orthogonal separation. This second separation happens in the time it takes to accumulate the next sample, or the modulation time. This allows for:

  • Low cost implementation of GCxGC
  • Simple, easy installation
  • Dramatically increased peak capacity through comprehensive analyte transfer
  • Unattended or remote operation
  • Streamlined operation through dedicated software
  • Straightforward switching between 1D and 2D GC

Product Note: Quasi-Stop-Flow Modulated GCxGC

Author: Tommy Saunders, Activated Research Company



By looking at the chromatogram of the 1D projection of biodiesel (above, left), the limitations of 1D GC are made clear and demonstrated through unresolved peaks and coelution. However, when comparing to the 2D heatmap projection of biodiesel (above, right), all of the peaks that have been resolved in the second dimension can be seen. This capability can be extremely powerful for complex matrices.

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