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Column life time: experiences

Posted: Sat Jun 28, 2008 4:34 pm
by LCFlo
Dear all,

I am interested in your experiences with columns of several brands regarding column life time. I am interested in information about the column name, mobile phase you use, column temperature and flow and the resulting experiences (long column life, extremly short column life, fast selectivity changes...)

Thank you very much for outlining your experiences.

Florian

Posted: Sat Jun 28, 2008 5:13 pm
by Stryder08
You might want to include what type of matrix you are extracting/injecting....

People who simply run neat standards or pharmaceutical compositions will have better column lifetimes, than those that extract postmortem or decomposed blood specimens...as an example.

Posted: Sat Jun 28, 2008 7:18 pm
by Uwe Neue
I agree with Stryder08. I have managed to get completely unchanged chromatography for over 10 000 analyses for a column protected by guard columns at pH 4.75, and I have killed a column instantaneously with an injection of undiluted milk. In between is the use of columns with plasma samples...

Posted: Sat Jun 28, 2008 8:13 pm
by LCFlo
Thanks for the prompt replies.

I am primarily interested in pharmaceutical analytics (solutions and tablets) as well as for experiences like:

"when I injected a simple matrix on column X, I had problems after 50 injections. But column Y was cool, it was possible to do 500 injections"

Florian

Posted: Sat Jun 28, 2008 11:51 pm
by Bruce Hamilton
IF you are interested in compendial pharmaceuticals you could look at the EP freely-available Knowledgebase, which details the columns used in the method development.

As a bored, impartial observer, I'd really enjoy reading a whole lot of badmouthing of various brands of columns, but I don't think I'd take any notice of the comments.

As noted above, the samples, sample preparation, and care of columns will have the most profound effect on lifetime.

In my experience, generally, for yucky samples, as the carbon chain length increases, column durability improves. A C8 column died after a couple of injections of fermentation media, whereas the C18 column lasted for a few hundred of the same muck.

I've always assumed that if a reasonable brand has been around a while, they will test their columns, rather than using the consumer as unpaid product quality testers.

Most of the few dodgy columns that I've encountered have come from the smaller, specialist, manufacturers.

Please keep having fun,

Bruce Hamilton

Posted: Tue Jul 01, 2008 10:33 am
by schelmar
Hi Bruce Hamilton

Where can i finde EP freely-available Knowledgebase im am often looking for it but i didn't find something

Marco

EP knowledge database

Posted: Tue Jul 01, 2008 11:48 am
by LCFlo
Hi schelmar,

Bruce meant the knowledge database of EP:

http://extranet.pheur.org/publications/ ... s_sw.shtml

As an example, when you search for amitriptyline, the following page is found:

http://extranet.edqm.eu/4DLink1/4DCGI/Web_View/mono/464

This could be useful for the start of method development.

Regards

Florian