Abstract
Evaporative light scattering detection (ELSD) is an inexpensive “universal” mode of optical detection for LC. We report here on ELSD as a useful adjunct to UV detection for the RP-HPLC peptide mapping of proteins. We use peptide mapping as a “finger-printing” technique to detect post-translational modifications and other small changes to recombinant protein pharmaceuticals. UV absorption and ELSD modes were run in series for a RP-HPLC tryptic map of the small “model” protein, cytochrome c. We also report preliminary ELSD data for the RP-HPLC tryptic map of an IgG1 monoclonal antibody.
ACKNOWLEDGMENTS
The authors are grateful to Joseph G. Phillips, Sonya Kennedy-Gabb, Lewis Killmer, and Paul Cummings for the use of the HP 1100 LC/MS system and their expert assistance. We also thank Thomas Cacchio, David Thornton, and Yunan Miao for help with the ELSD instrumentation and Maggie M. Huang for helpful discussions.