I would like to estimate the contents of glutamine and glutamic acid in fruits of tomatoes, preferably with the use of HPLC as we don't have a specified amino acid analyzer.
You can label the two amino acids with AccQ-Tag Ultra Chemistry Kit from Waters. Afterwards the labeled amino acids can be seperated on C18 column and detected by UV. It is better to analyze them with a UPLC. If you have a ELSD or MS detector connected to a LC, you may also seperate them on a HILIC column without deriviativation.