I use to run a method to analyse all the amino-acids in a food sample. For that I have to hydrololyse the sample and in the last stage of the method I read the amino acids with a ion exchange chromatography. However, when using this method, due to the hydrolysis, the glutamine transforms into glutamic acid, thus in my result I get a big peak for glutamic acid and I cannot read glutamine.
My question is if there's a method to quantify glutamine in a food sample.
Edit: it has been a while, thanks for the feedback! In the kind of samples I have I need to measure the bound glutamine, not free glutamine. This imposes a problem during sample preparation when trying to separate the amino acids. I have made a few experiments and I have almost succeeded by using a 'enzyme cocktail' that does a total enzymatic hydrolysis. Next step will be to find out if I can quantify glutamine.