How to analyse amino acids in the presence of Cu(II) complex

[river]

Hello,
I used dabsyl-Cl for dirivatization to determine amino acids by using HPLC. However, there was no expected peaks in the chromatogram. It could be the interference of the Cu(II) complex in the reaction mixture (Cu(II) complex was used as the catalyst for the cleavage of peptides and it is paramagnetic). I do not know whether I can change the derivatisation reagent or remove the complex before derivatisation. AccQ-Tag is suitable for this case because it is said that salts do not interfere with the derivatisation reaction? How can I remove the complex?

I am waiting for help from all of you.
Thanks in advance.
River

[HW Mueller]

Don´t you have an aminoacid solution which does not have the Cu complex, for testing? In other words, this is another example of trying to do HPLC without standards?

[river]

Thanks for your reply.

In the absence of the complex, the standard amino acid was detected, but it was not detected in the presence of the complex at the same experimental conditions.

[HW Mueller]

Well, then it is clear as to what you have to do. Not knowing what this Cu complex is I can´t help further, if it is charged a simple ion exchange should get rid of it.