Has anyone had any success with GC of trace amounts (<100ppm) of TFA or acetic acid? I've just started investigating but had no success with TFA yet. The matrix will likely be water, but could be DMSO of DMF/other polar solvent if it was necessary. Detection looks most likely by MS.

ta

I would investigate NMR and/or LC to do this analysis well, it depends upon your matrix and accuracy requirements.

Rodney George
Senior Research and Development Scientist
Gas Separations Research
Supelco
595 North Harrison Road
Bellefonte, PA 16823

814-359-5737 voice
814-359-5702 fax
rgeorge@sial.com

If you don't have access to LC or NMR then consider derivatisation to a methyl ester. see below. Perhaps use a wide bore thick film column like Supelcowax.

Simplified method for trace analysis of trifluoroacetic acid in plant, soil, and water samples using headspace gas chromatography
Cahill TM, Benesch JA, Gustin MS, Zimmerman EJ, Seiber JN
ANALYTICAL CHEMISTRY
71 (20): 4465-4471 OCT 15 1999

Abstract:
"A simple and sensitive analytical procedure was developed to determine the concentration of trifluoroacetic acid (TFA) in plant, soil, and water samples. The analysis involves extraction of TFA by sulfuric acid and methanol followed by derivatization to the methyl ester of TFA (MTFA). This is accomplished within a single vial without complex extraction procedures. The highly volatile MTFA is then analyzed using headspace gas chromatography. The spike recovery trials from all media ranged from a low of 86.7% to a high of 121.4%. The relative standard deviations (RSDs) were typically below 10%, although some tests had higher RSDs due to low concentrations near the detectable limit. The minimum detectable limit (MDL) for the method was 34 ng/g for dry plant material, 0.20 ng/g for soil, and 6.5 ng/L for water, This is the first practical method for low-level analysis of TFA in plants and soil, and it is a significant improvement over previous methods for TFA in water."

Regards,

Ralph