What the method does is periodically direct small aliquots of solute from the outlet of one column into the inlet of another column. The columns are chosen so that one retention mechanism in the first column (dimension) is vastly different than the retention mechanism in the second column (dimension). Examples typically include a reversed-phase (RP) column in the first dimension followed by a size-exclusion column in the second or an ion-exchange column in the first dimension followed by a RP column in the second dimension. Detection is typically a UV detector or evaporative light scattering detector. This technique becomes even more powerful when a UV diode-array detector and/or a mass spectrometer are used. The data are typically plotted as concentration contours as follows
:
Brochure of the LCLC system (pdf)
The 2DLC method has largely been practiced and developed by academic scientists who have looked at basic separations and have developed a number of protocols for use with this technique. The problem for increased utilization of this technique has been the lack of available turnkey solution software and hardware. That was the past.
With LCLC from Kroungold Analytical, Inc., we introduce the key components solution to the implementation of multidimensional chromatography. This includes both software and hardware for valve control, data processing, data analysis, data presentation and methods development. Mass spectrometry data handling is also included as an integral part of the software offering! The hardware component includes start/stop sequencing, external valve controlling and autosampler controller functions.
This allows one to assemble off-the-shelf components to form a total 2DLC system at a fraction of the cost that one might normaly expect. For example, simply add one or two specified valves, add an extra HPLC pump and a second column and the 2DLC capability can be yours.