Particulate Flushing

[RLH]

When the system backpreasure begins to rise due to particulate accumulation in an analytical column, we just reverse the column. The presure resets to normal and the tailing peak shape improves. We continue to run in this reverse direction until the presure begins to rise again (1000 injections) and then just flip the column. Is the stated flow direction of the column significant?

[tom jupille]

Depends on the column. Most 5-micron columns (or larger particle sizes) can be reversed without any problem (the flow direction arrow simply provides a point of reference). Many smaller-particle columns, however, are asymmetric, using different frit arrangements on the inlet and outlet.

Best bet is to check with the manufacturer of your specific column.