I have a question

[pamelaquimica]

Hi I have a question:
Which is the most appropriate column for the separation of amino acids, I'm using a column C18 of 4.6 x 200 mm and 5 microns.
I have not achieved an excellent separation then I think it may be due to the column because I have changed many things and does not improve.
thanks!!!

[skunked_once]

The answer to your question is "It depends." The choice of column depends on which amino acid derivatives you are preparing as well as which mobile phases are being used.

Are you using one of the HPLC vendor's standard methods? If so, the column and conditions are specified.

Are you trying to adapt/adopt a method from the literature? Again, the column that was used should be specified.

If you give us as much information as you can about the method you are using, we can be much more helpful.

[tom jupille]

Unless you want to "reinvent the wheel", my suggestion would be to check with your favorite column vendor and obtain from them a column dedicated to amino acid analysis and a recommended procedure.

[JGK]

Amino Acid analysis can be a tricky business and the results can vary dramatically depending on which technique you are using.

Our lab has been participating in a 14 lab multi-site study comparing method types using the same hydrolysatem samples to measure a 15 AA panel. Labs were using HPLC & UPLC with UV or Fluorescence and LC-MS-MS methods. Sample prep by either Pre or post comn derivatisation.

From the results, the post columm derivatization based methods produce the greatest measurment errors.