PARALLEL CRYOGENIC TRAPPING MULTIDIMENSIONAL GAS-CHROMATOGRAPHY WITH DIRECTLY LINKED INFRARED AND MASS-SPECTRAL DETECTION

This paper describes successful implementation of multiple trap multidimensional gas chromatography (GC) directly linked with parallel Fourier transform infrared (FT-IR) and mass spectroscopy (MS) detectors. For complex mixture separation, six parallel cryogenic traps are interposed between a first-stage GC pre-column and a second-stage GC analytical column. With proper choices of heart cut time intervals, this multiple parallel cryogenic trap approach allows expansion of the practical analytical dynamic range and accommodates the separation constraints of a combined GC-FT-IR-MS system. An unleaded gasoline sample is analyzed with respect to the degree of secondary separation and to the reproducibility of adjusted retention times. The results of cryogenically trapping heart cuts using both with 72- and 12-s trapping times are presented. Shortening the trapping times from 72 to 12 s results in a significant improvement in the analytical column separation and identification with infrared and mass spectra. Thus, use of multidimensional separation coupled with multispectral detection may provide increased reliability of complex mixture component identification.