I´m trying to find a method to quantify acetonitrile, acetamide and acetic acid in a aquous mixture.
I have tried to use gc and it worked well with a pure mixture of the three components. The problem is that the real samples have also inorganic salts dissolved and I was told that it will ruin the column very fast. I have tried to extract the components with organic solvents but only acetonitrile was satisfactory extracted.
Now I´m thinking using hplc to solve my problem.
I think that it is possible to detect any of the components with an UV detector. Is it known any column/method that could separate and quantify those components? Or at least acetamide and acetic acid since it is possible to quantify acetonitrile with GC.
Thanks in advance.
By B.Buglio (hopepm00.bbsnet.com - 126.96.36.199) on Thursday, July 29, 1999 - 09:44 am:
The mehtod of choice for these three analytes is GC. To eliminate inorganic salts you might try passing the sample thru an ion extraction disc such as Novoclean offered by Alltech.
By PetrM on Tuesday, August 3, 1999 - 05:23 am:
Let s try the direct injection of your sample into the packed GC liner (with glass wool) at low temperature. The salt wilt be catched at the glass wool and organic analytes wil be evaporated and transferred into the column. Of course, you have to clean you liner periodically. I used this system for acetic acid determination in peptides (FFAP column from HP). It has been working for a while.
By scalislar on Tuesday, September 14, 1999 - 07:12 am:
I am a researcher in Turkey at KSU. I need to information about to
acetic acid and butiric acid analysis methods by gas chromatography inthe silage. Could you send me about them.
By Anonymous on Tuesday, September 14, 1999 - 04:25 pm:
You will get a better response if you re-post this on the GC message board. Many people read one or the other, but not both.
By David McCalley on Wednesday, September 15, 1999 - 08:37 am:
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.
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