I am trying to measure acetic acid and have been told that the best way to do this is to use a GC. Unfortunately, I have never used a GC and I am looking for a standard method for the analysis. If anyone could either outline the method or give me a reference for it I would greatly appreciate it.
By Anonymous on Thursday, October 14, 1999 - 07:59 pm:
I pulled this off an earlier thread; hope it's useful.
>It is possible to analyse aqueous solutions of free fatty acids by capillary gas chromatography. However, packed column GC is very robust when using dirty samples like silage. We did a lot of work on this in the 1980s. We found that a column packed with graphitised carbon black coated with Carbowax 20M gave very good results-better than on porous polymer type columns. The method is detailed in "Determination of volatile fatty acids and lactic acid in silage by GC" R.J. Fussell and D.V. McCalley, Analyst 1987 112 1213.
David McCalley <
By Wilhelm leung on Friday, October 15, 1999 - 07:04 pm:
Look up the MN HPLC application guide. There is a reference for the determination of acetic acid using MN C18 5u 4.6X250mm column with a 10mN sulphuric acid as the mobile phase at 200nm. I had used this method. It's OK but you need to clean your system thoroughly and have to equilibrate for half a day. Another approach is to use an ion exclusion column - refer to the Alltech catalogue for conditions. This also works well. Good luck!
By Rachel on Wednesday, October 20, 1999 - 05:03 am:
It is possible to do the analysis by HPLC.
You'll need an RI detector and a polymeric (SDVB) Carbohydrate H+ column - for example ThermoQuest's HyperREZ Carbohydrate H+ column. Using 2.5mM sulphuric acid as the eluent you get a nice peak shape.
Posting is currently disabled in this topic. Contact your discussion moderator for more information.