OPA/MPA derivatizatio stability for amino acids

[dragosb]

Hi,

I would like to know if the OPA/MPA derivatization results in stable products or is there something more I can do to avoid secondary derivatization products.

Please let me know about your opinion on this and what is your experience with the OPA/MPA derivatization.

Thank you very much

[PeterS]

As far I know the products are not quite stable, so the best is to derivatize just before use in a time controlled situation. At least then there is a compareable situation between samples

Peter

[Kristof]

As good as I know problem is not with secondary derivatization but with decrease of signal strenght in time due to decomposition of fluorescent product into non-fluorescent one.

With right type of autosampler you can run injector program that would perform OPA/MPA derivatization for you just before injection. I know Agilent 1100/1200 can do this.

For stable derivatization look at fluoresceine (less sensitive as good as I know) or AccQ Tag from Waters.

[JGK]

As good as I know problem is not with secondary derivatization but with decrease of signal strenght in time due to decomposition of fluorescent product into non-fluorescent one.

With right type of autosampler you can run injector program that would perform OPA/MPA derivatization for you just before injection. I know Agilent 1100/1200 can do this.

For stable derivatization look at fluoresceine (less sensitive as good as I know) or AccQ Tag from Waters.

Check out the Pico tag from Waters if you have a standard HPLC. AccQ tag is for UPLC instruments.