What is the recommended number of column volumes to clean a column during a gradient run? - WKB51034

ENVIRONMENT

• Column cleaning
• Gradient runs

ANSWER

A minimum of three to five column volumes are recommended for cleaning a column between gradient runs. This must take into account the dwell volume in the LC system. 

ADDITIONAL INFORMATION

This article discusses how many column volumes to clean a column during a gradient run.  This means that for a reversed-phase column, for example, a high percent of organic is flushed through the column in order to clean hydrophobic compounds off of the column.

A column re-equilibration will then need to be performed during the gradient table in which the gradient returns to initial conditions, for example 95:5 Water:Acetonitrile for a reversed phase column. Waters recommends to re-equilibrate a reversed-phase column for 5 to 10 empty column volumes at the end of the gradient table.

For additional information, see the articles How do I calculate the empty column volume of a column? and How do I determine system dwell volume?