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

Increases in peak capacity that are achieved using comprehensive rather tha n single-column gas chromatography are also often accompanied by significan t improvements in minimum detectable amounts. Comprehensive gas chromatogra phy utilizes a zone compression of eluent between primary and secondary chr omatography columns, with complete conservation of mass. In this paper, we present a theoretical model of peak amplitude enhancement based on translat ion of the fractional area under the primary column normal curve to a secon dary Gaussian peak. Amplitude enhancement made by peak modulation scales wi th increasing modulation period and primary column peak width. An exponenti al relationship between the modulated secondary column peak width and the a mplitude enhancement is also observed. The calculated amplitude gains are f urther corrected for detector current noise generated via flame ionization detection at a range of operating frequencies. An example of trace level at mospheric analysis is used to demonstrate both peak capacity and sensitivit y enhancements using the multidimensional technique.