Q: How do I clean a clogged GPC column?
A: When the backpressure in a GPC system is higher than usual, try to single out the problem by testing each column individually and see if either one is causing the pressure increase.
If you have identified a column, try cleaning it by flushing against the flow at reduced flow rate (0.1 ml/min) Until the impurity is removed. Be careful to not attach any detectors when doing so.
In addition, changing the polarity of the solvent can also help dissolve blockages.