A model of peak amplitude enhancement in orthogonal two-dimensional gas chromatography

Increases in peak capacity that are achieved using comprehensive rather than single-column gas chromatography are also often accompanied by significant improvements in minimum detectable amounts. Comprehensive gas chromatography utilizes a zone compression of eluent between primary and secondary chromatography columns, with complete conservation of mass. In this paper, we present a theoretical model of peak amplitude enhancement based on translation of the fractional area under the primary column normal curve to a secondary Gaussian peak. Amplitude enhancement made by peak modulation scales with increasing modulation period and primary column peak width. An exponential relationship between the modulated secondary column peak width and the amplitude enhancement is also observed. The calculated amplitude gains are further corrected for detector current noise generated via flame ionization detection at a range of operating frequencies. An example of trace level atmospheric analysis is used to demonstrate both peak capacity and sensitivity enhancements using the multidimensional technique.