Chromatography Forum

Hi guys,
I am confusing about what to do to my “forgotten to cap after being used” column. It’s been more than 2 weeks left opened and now I’m gonna used it again.
I think it’s dried out.
I am worried my supervisor gonna kick me out of lab after finding it out.
Any suggestion ?
My column is TOSOH 4.6mmx30cm and the mobile phase I use is ammonium acetate and it is washed by NaN3 0.02%. I’m not sure, but I’m trying to rehydrate it with my mobile phase. Is that making it worst ?

1. Try the column and see if it still performs as it should. It might be OK after all this.

2. Even though HPLC columns are expensive, you and your supervisor need to realize that these are CONSUMABLE ITEMS, just like vials, filters, etc. When one calculates the cost of the column per sample or injection, it's typically not that high, just looks like a "big hit" when it gets ordered compared to a package of autosampler vials or similar. I always had a brand-new spare column in-house to throw in for either troubleshooting or to have on hand if a column no longer performed. Maybe part of your job will be to educate the supervisor that these are consumable items. I'm also betting that you never forget ever to cap a column !

3. That said: several times I came across a column left uncapped in our lab, and can't respond that these were all or dead, or even a majority of them. This happened a lot in the 1980s-1990s when we used modular reverse phase columns from a company named Brownlee, later bought out by Perkin-Elmer; these columns did not have a screw-in end fitting, they fit in a holder, so the 1/4 inch o.d. tubes were simply "capped" by a little vinyl cap. So these frequently were left open to the air by neglect.

Hi, andriana,

From Neue's troubleshooting guide:

http://www.waters.com/webassets/cms/lib ... a20769.pdf

see page 23 Section 17. I'm with Consumer Products guy, you'll be okay.

Hi Matt the consumer guy,
Thank you for the suggestion. It blew some questions away.
Fortunately , the column seems okay after overnight conditioning by the buffer I usually use.
the pressure’s getting higher a little, but may be it’ll be okay. I’m not sure. I’ll keep going with this purification.

Thank’s

Hi, andriana,

I apologize to you and the real Consumer Products Guy for causing confusion--was only saying that I agreed with him.

Good to hear your column is likely in good shape--stuff happens.

Hi Matt,

I see. Sorry, my bad since English isn’t my mother tongue, so many misunderstandings come to my life lol

Thank’s anyway to both of you guys, Matt and consumer guy.

Two weeks isn't too bad. It normally takes much time for the liquid, especially if it is water, to evaporate from the entire column. It is a very tiny orifice at the opening and for the water to migrate through the packing material is not easy, so it tends to stay inside the column for a long time.