I have a problem with amino acid derivatives in the form of succinimide
esters, as they often contain some beta-alanine, sometimes up to 3 %.
The method of analysis I use is quite standard post-column
derivatization on a Biotronik (Eppendorf) instrument.
At first I attributed this effect to the hydrolysis procedure i.e. that
beta-alanine forms somehow in the analysis, but now I to have confirmed
that the impurity is present in the samples from the start. That
indicates that the manufacturing process of the derivative is
responsible, or maybe a degradation process. What puzzles me is that not
all samples of Su esters (comparing different batches and manufacturers)
contain beta-alanine.
Does anyone have any suggestions about what is happening?
Aleksander Swietlow
Polypeptide Laboratories (Sweden) AB
email: aleksander.swietlow@ebox.tninet.se