multidimensional chromatography

The use of two or more columns or chromatographic techniques for improved separation. It is useful for sample cleanup, increased resolution, increased  throughput, and increased peak capacity. It  can be used off-line by collecting fractions  and reinjecting them onto a second column or on-line by using a switching valve.  Also called coupled column chromatography,  column switching, multicolumn chromatography,  and boxcar chromatography.