By Anonymous on Thursday, June 3, 2004 - 04:21 am:

I am hoping to set up an SPE method for the isolation of organic acids from urine (which are then detected using GC/MS). Does anyone have any experience of using SPE for organic acids or similar analytes? Any comments will be gratefully received

TIA

Helen.

-------------------------------------------------------------------------------------------------------
By A.Mouse on Friday, June 4, 2004 - 12:10 am:

This is best done with an anion SPE, something with a quaternary amine bonded. There are methods on the Waters webside for their Oasis ion-exchangers. We have used them for our problems and they worked well.

-------------------------------------------------------------------------------------------------------
By AllsepTech on Friday, June 4, 2004 - 05:26 pm:

For direct analysis, retention and separation of acids in various biofluids check the link below. Primesep D column is specially designed for analysis of acidic molecules in biofluids. It also retains hydrophobic compounds but repells proteins:
http://allsep.com/Technology_DirectPlasmaAnalysis.php
Mobile phase is LC/MS and preparative chromatography compatible.

-------------------------------------------------------------------------------------------------------
By Ingo Christ on Tuesday, June 8, 2004 - 06:53 am:

I have worked with horse urin samples. For that work I used a Spark Holland SPE system and developed a method to first get the acids and then the bases. Several cleaning steps made the chromatography clean and my recoveries were above 90%. Call me if you want to get more details
Ingo @ 703/780-1500 (CHROMSYS.com)