Agilent Technologies InfinityLab LC Series User Manual page 21

1 Introduction to the Multicolumn Thermostat
Typical Applications
Advantages:
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Sample cleanup is essential for samples with complex matrices, such as
biological fluids, food extracts and waste water. Before injection into a LC or
LC/MS system, the sample matrix must be separated from the analytes of
interest. Otherwise, contaminants can disrupt separation and detection or even
damage the analytical column.
Enrichment methods
Enrichment methods are the techniques of choice to obtain highest sensitivity
and to remove the sample matrix in such applications as proteomics, drug
metabolism, and environmental trace analysis. The analytes are retained and
concentrated onto the precolumn, while the sample matrix is passed to waste.
After the valve switch, a second pump backflushes the analytes out of the
precolumn onto the separation column. This allows injection of large volumes
onto the precolumn, significantly expanding sensitivity in the range of ten to
several thousands.
Sample cleanup
Cleanup methods handle analytes and matrices in the opposite way to
enrichment methods. Matrix components are retained on the precolumn while
the analytes pass through to the separation column. After the valve switches, an
extra pump backflushes the matrix components out of the precolumn to waste,
while the analytes are separated on the main column. Backflushing prepares the
precolumn for the next injection.
Agilent InfinityLab LC Series Multicolumn Thermostats User Manual
Easy automation of sample preparation
Higher reproducibility
Increased productivity and sensitivity
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