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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Golden_4_Life on January 04, 2010, 11:13:02 AM

Title: Necessary to filter mobile phase?
Post by: Golden_4_Life on January 04, 2010, 11:13:02 AM

If the solvent bottle says "passed thru a 0.25 micron filter", then why is it necessary for me to have to filter thru a 0.5 micron filter?  Pls correct me if I am mis-stating this, but does it not render it unnecessary then to have to re-filter thru a filter that is of a wider bore than what the solvent was manufactured?

Title: Re: Necessary to filter mobile phase?
Post by: doc30 on January 04, 2010, 01:25:43 PM

You never know if contamination can get into your HPLC. Columns are expensive so it's always a good idea to keep your solvents as clean as possible.

Title: Re: Necessary to filter mobile phase?
Post by: Golden_4_Life on January 04, 2010, 02:38:05 PM

Thanky DOC---yet, I shall continue to filter notwithstanding the irrelevancy of it in this particular case.

Title: Re: Necessary to filter mobile phase?
Post by: JGK on January 05, 2010, 12:20:30 PM

The solvent may well have been filtered during its manufacture but you cannot rule out the possible entry of inert particulate matter during:

The bottling process;
Once the container's seal has been broken for the first time;
During mobile phase preparation.

Filtration following preparation eliminates these possibilities.