James Frahill, who is a Research Analyst at the Pfizer Process Development Centre (Cork, Republic of Ireland) spoke to Bethany Degg of The Column about the role of the chromatographer in the pharmaceutical process development group at Pfizer.
Q. What are the main objectives of your research group?
Typically, the methods developed during the process development are evolved into the analytical test methods that are validated and are filed with regulatory bodies during the process filing.
In the drive to get better process understanding the analytical group leverages any useful technology available in the market place to deliver the results required. We have recently expanded our collection of detectors by adding a charged aerosol detector (CAD) and a quadrupole time-of-flight (Q-TOF) mass spectrometer to our array of orthogonal chromatography systems which include reverse-phase high performance liquid chromatography (HPLC) and ultrahigh-pressure liquid chromatography (UHPLC), non aqueous reverse-phase HPLC, normal phase HPLC, and supercritical fluid UHPLC.
Q. What is the focus of your research at the present time?
A: At the moment I am working on impurity identification. I am analyzing samples generated by our new process chemistry using LC–QTOF-MS. I use the high resolution of the instrument in MS mode to generate the molecular formulae for the peaks of interest. We then conduct MS–MS experiments on each of the impurities and determine the structure of the impurities by assigning structures to the fragment ions generated in the MS–MS experiment.
Nobody can claim to be able to do de novo structural elucidation using MS and MS–MS data alone, but given the limited amount of transformations possible in a pharmaceutical chemistry reaction, we can elucidate structures from the data with a high degree of confidence. We then synthesize the proposed structure and confirm its identity under the original analytical technique.