Column Life on Storage

[syx]

Dear Members,
When a column is stored for a long time (more than 1 year) in recommended solvent without injection, will the column life time still be reduced?

Best regards,
Siswanto Tanuatmojo

[Uwe Neue]

That depends on the storage conditions recommended. If the storage conditions were well designed, no change chould have occured to the column over this time, and the column should perform equally well as when it was used the last time.

What column are you referring to, and what storage conditions have been used?

[syx]

What column are you referring to, and what storage conditions have been used?

I mean column in general. Each type of column needs different storage solvent. For example: recommended storage solvent for Phenomenex’ reverse phase C18 columns is 65% acetonitrile and 35% water. But I tend to use 100% organic solvent (methanol or acetonitrile) and then the column is capped tightly.

[DR]

We typically use anywhere from 50-80% organic (ACN or MeOH) as a storage solvent for a wide variety of RP columns and have had no problems attributable to storage solvents. As long as there are no chemistry altering MP modifiers and/or buffers in there, they really aren't that picky (generally). I would anticipate no problems with using higher organic concentrations.

[Uwe Neue]

If your reversed-phase column is stored in pure acetonitrile, absolutely nothing will happen to the column, and it will look the same after storage compared to before storage. If you store the column in something that contains water, you will get a slow change of the column properties. Over a year's period of time this change will be measurable.

We (Waters) store virtually all of our reversed-phase columns in acetonitrile and recommend to our customers to do the same for long-term storage.

[syx]

It sounds like the problem will come from the water content in the storage solvent? What if we use pure methanol instead of acetonitrile?

[HW Mueller]

syx, methanol reacts like water which has one hydrogen replaced with a methyl. ACN behaves more like a methyl with a halogen attached (in the present context).

[Uwe Neue]

Syx, we have not tested methanol, so I do not have a well founded opinion on it. We have tested acetonitrile, in both accelerated testing and real tests and found it to be suitable.

I agree with Hans. I would not select a protic solvent.

[syx]

Mr. Hans and Mr. Neue, thanks for the explanation.