ENHANCED POSSIBILITIES FOR IDENTIFICATION BY THE USE OF SERIES-COUPLED CAPILLARY GAS-CHROMATOGRAPHIC COLUMNS .1. GENERAL EXPOSITION AND APPLICATION OF THE RETENTION INDEX CONCEPT

After a short survey of the variants of multi-dimensional gas chromatography resulting from the combination of different columns and operating parameters, the possibilities of the use of the retention index concept in systems of series-coupled columns without intermediate trapping for the identification of individual components in complex mixtures are discussed. This technique allows a greater reliability of chromatographic identification by the use of the retention index concept for the simultaneous determination of Kováts retention indices on the two columns, the calculation of isothermal retention indices on the second separation column with temperature-programmed operation of the first column and the predetermination of system retention times of individual components on the basis of known retention indices on either column alone. © 1990.