Impurity and Degradation Product Identification

WLI operates a state-of-the-art ion trap/triple quadrupole Applied BioSystems 4000 mass spectrometer, which is mated to an HPLC system.  We routinely use our HPLC/MS/MS capabilities to profile and identify unknown sample components. 

An impurity identification study may be an extension of a stability-indicating method development program,  a part of a program to identify leachable/extractable impurities, or a stand-alone project.  An example of an impurity identification project is confirmation of structure of a synthetic byproduct discovered in a new batch of API. 

Typically, our approach involves installation of a suitable HPLC method or modification of an existing method for use with volatile buffers that are compatible with a mass spectrometer.  The goal is to assure adequate separation of the active ingredient and the impurity or degradation product(s).  Once separation is achieved, we obtain the full scan and MS/MS spectra of the active ingredient, additional standard, and the impurity/degradation product(s) of interest.  This approach helps develop a relational understanding of molecular structure to mass spectrometric fragmentation patterns, which then are used to identify putative structures.