PTFE & Cellulose Filters [May 21, 2004]
Posted: Wed Aug 25, 2004 3:41 am
By Anonymous on Friday, May 21, 2004 - 07:59 am:
I use filter cartridges (luer tip) to filter juice / drink type dilutions prior to HPLC analysis. I currently use PTFE which I know is not suitable but the recovery for my analytes is near 100% each time (although they block easily). I have used regenerated cellulose too - which are for aqueous use. The recovery is good too - without the blockage. They are very expensive.
I have tried all the other common filter materials.
Does anyone know of a cheaper alternative - perhaps in another format??
-------------------------------------------------------------------------------------------------------
By Ingo Christ on Friday, May 21, 2004 - 12:01 pm:
Try the Mini UniPrep vials from Whatman. They are the same size as 2mL vial and don't need the syringe, syringefilter and glass vial. They also fit in your autosampler. I believe they cost approx. $1.50.
I actually automated the filtering process with the Mini UniPrep using a commercially available autosampler. Works really great.
-------------------------------------------------------------------------------------------------------
By ad on Monday, May 24, 2004 - 07:40 am:
how did you automated the filtration proces ingo?
-------------------------------------------------------------------------------------------------------
By Anonymous on Sunday, July 4, 2004 - 06:04 pm:
Is a glass filter material the best material to filter mobile phases through?
-------------------------------------------------------------------------------------------------------
By Anonymous on Monday, July 5, 2004 - 12:29 am:
It has been said that the glass fibres can leach off the paper and into the filtered sample so can find their way to damaging pump seals,pistons etc.
I dont have a reference for this - just something I came across a while ago.
HPLC Dave
I use filter cartridges (luer tip) to filter juice / drink type dilutions prior to HPLC analysis. I currently use PTFE which I know is not suitable but the recovery for my analytes is near 100% each time (although they block easily). I have used regenerated cellulose too - which are for aqueous use. The recovery is good too - without the blockage. They are very expensive.
I have tried all the other common filter materials.
Does anyone know of a cheaper alternative - perhaps in another format??
-------------------------------------------------------------------------------------------------------
By Ingo Christ on Friday, May 21, 2004 - 12:01 pm:
Try the Mini UniPrep vials from Whatman. They are the same size as 2mL vial and don't need the syringe, syringefilter and glass vial. They also fit in your autosampler. I believe they cost approx. $1.50.
I actually automated the filtering process with the Mini UniPrep using a commercially available autosampler. Works really great.
-------------------------------------------------------------------------------------------------------
By ad on Monday, May 24, 2004 - 07:40 am:
how did you automated the filtration proces ingo?
-------------------------------------------------------------------------------------------------------
By Anonymous on Sunday, July 4, 2004 - 06:04 pm:
Is a glass filter material the best material to filter mobile phases through?
-------------------------------------------------------------------------------------------------------
By Anonymous on Monday, July 5, 2004 - 12:29 am:
It has been said that the glass fibres can leach off the paper and into the filtered sample so can find their way to damaging pump seals,pistons etc.
I dont have a reference for this - just something I came across a while ago.
HPLC Dave