2D-LC User Guide
37
2
Concepts of 2D-LC
Active Solvent Modulation (ASM)
Operating Principle
Figure 18
Operating principle with sample loop in flow
path (schematic view)
Figure 19
Operating principle with sample loop and ASM
capillary in parallel flow path (schematic view)
1
D Solvent in the sample loop is partially diluted by
2
D solvent
from the
2
D pump.
*
Introducing a parallel flow through an ASM capillary strongly
dilutes
1
D solvent with weaker
2
D solvent. These solvent
conditions focus the sample on the head of the
2
D column
and therefore enable a good separation.
*
*
red:
2
D solvent from
2
D pump, blue: sample with
1
D solvent in sample loop
