I somewhat routinely get asked to assay free fatty acids from acetic up to stearic. I sometimes do a headspace esterifcation for acetic through caproic and HCl/methanol for larger chain acids. I am curious how I would use a free fatty acid column. I have a 5890-FID with ALS sitting vacant. I am usually loathe to inject water as most of my samples are loaded with salts, carbohydrates, amino acids, proteins, and humic compounds. How would I prep? It would certainly be nice to do a simple prep and inject without derivatizing.