By Anonymous on Thursday, January 24, 2002 - 07:11 am:
i am go na validate a gchs method for my bulk sample as a part of my DMF SO I HAVE TO SET THE METHOD FOR 8 SOLVENTS IN A SINGLE RUN AND I AM SUCCESSFUL FOR A GREAT EXTENT BY DOING THAT BUT PROBLEAM IS I AM NOT GETTING A LINEARITY AND RECOVERY AND PRECISON FOR THIS TWO SOLVENTS SO I AM GIVING A DETAL WHATS MY METHOD CAN YOU ASSIST WHAT CAN BE THE PROBLEAM
By Rodney on Friday, January 25, 2002 - 06:55 am:
The problem may be you are forming a salt with the acetic acid. I have done TEA acetate in peptides with linearity with a LOD of 50ppm (measured as the free base). R2=0.9998
This was from DMSO/water not DMF.
Do the acetic acid separately by ion chromatography as the acetate.
A purge and trap GC-MS method for TEA gave 0 ppm for samples I later discovered contained several hundred ppm of TEA-acetate.
Good luck, it ain't easy.
Rodney George
Gas Separations Research
Supelco
By Montse on Monday, February 18, 2002 - 05:45 am:
I have no experience with TEA, but I had the same problem with acetic acid. I solved it changing from an OVI-G43 column (6%cyanopropylphenil-dimetylpolysiloxane) to a DBWAX, which gives higher and more symmetric acetic acid peaks.
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