Hi,

Which eluent do you use with your column ?

Have you tried with ethanol 80% or acetone 50%?

I used DCM/MeOH (1/1 - v/v) during my experience.

I haven´t tried with ethanol 80% or acetone 50%

Have you tried 0.2 M NaOH at a low flow rate (0.3 mL/min), then a water wash, then 0.2 M HCl, followed again by a water wash? You can always contact GE Health tech. support, they are very knowledgeable and helpful.

Gary Laco, Thank you very much for the suggestion

Water is a polar solvent which only removes specific impurities. So try using solvents like ethanol, acetone with or without water in specific proportions or even low polarity solvents. Further as suggested by Gary Laco use acidic and alkaline eluants with low molarity. This will definitely helps in removing lot of impurites.

I'll just add to the suggestions above- if you wash with something other than your eluting solvent, I suggest unpacking the column and wash/filter the media. This is because LH-20 swells differently in different solvents. Depending on how the media behaves in a given wash solvent, it will either expand or shrink from the current swelling, causing issues the next time you run the column. I once split a glass column from LH-20 that swelled inside the column.

After washing (if you use NaOH or HCl as suggested above, wash several times with water to remove the acid or base), let it dry, swell again in your mobile phase, and repack the column.

Wash the column with mild acid, followed by distilled water and finally wash the column with desired solvent system.

Till now I have unpacked the column and washed it with Acetone 100%. it's right that it eliminated some dirty. but the LH-20 is still dirty. (The color is still brun)

Actually, i wash it with 0.2M NaOH, and we wait for the result.

Thank you everyone for your kindly suggestion

The most steps to wash the LH-20 is one of Gary Laco. Thank you all for your kindly suggestion