Pulse Flow Modulation for Multidimensional GC

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Researchers from the University of Washington, USA, have developed an ultrafast separation using pulse flow valve modulation to enable high peak capacity in comprehensive two-dimensional gas chromatography (GC×GC) and three‑dimensional gas chromatography (GC×GC×GC) (1).

With the advent of multidimensional GC, increased peak capacity and chemical selectivity became available to researchers who required significantly more analytical clout in the laboratory. However, the cost of this extra power came in the form of a high likelihood of unresolved analytes. While this could be overcome by adjusting the sample throughput cycle, in cases where multiple samples required analysis, it was not ideal to have increased run times and cool down times.

The problem is further exacerbated when researchers seek out increased selectivity from higher order instruments, such as GC×GC×GC systems; the trade-off between increased selectivity provided by the three separation dimensions and peak capacity reaching new heights.

One promising area of research to address these challenges is modulation technology, with a recent report using pulse flow valve modulation to produce more optimal separation conditions (2).

Building upon this report, researchers used pulse flow valve modulation with GC×GC and utilized the results to advise the use of pulse flow valve modulation in GC×GC×GC.

The results of the research suggest that using a high temperature diaphragm valve modulator in conjunction with a recently introduced pulse flow valve modulator enables researchers to take advantage of the increased selectivity of GC×GC×GC instruments while achieving peak capacity production approaching 1000 peaks/min.

Researchers also indicated that future studies will be focused on applying these instrumental improvements with mass spectral data to create an ultra-fast four-dimensional data structure to address complex separation mixtures.

References

1. H.D. Bahaghighat et al., J. Chroma. A1573, 115–124 (2018).
2. C.E. Freye et al., Talanta117, 142–149 (2018).