This invention is a method and device for use with multi-dimensional
chromatography that utilizes partial modulation with multiple secondary
retention times. An analyte-bearing sample is subjected to a first
dimension of chromatography. Thereafter the separated analyte-bearing
sample is diluted with a modulated second carrier such at the
analyte-bearing sample is not stopped or its temperature altered. The
secondary retention time period at which the modulator cycles is variable
among multiple secondary retention time periods to prevent loss of
resolution with less complex and/or low boiling point compounds and to
prevent loss of data with more complex and/or higher boiling point
compounds. The partially modulated analyte-bearing sample then feeds into
a secondary column where the analyte-bearing sample is further separated.