LCGC Europe-10-01-2004

Column Watch
LCGC Europe

October 01, 2004

Column Editor Ron Majors turns his attention to preparative chromatography. He focuses on the columns used in preparative chromatography, including how to select the appropriate mode, mobile-phase system and operating conditions.

LC Troubleshooting
LCGC Europe

October 01, 2004

Are you guilty of strange troubleshooting and maintenance habits that have been passed on to you from predecessors? John Dolan looks at some such practices, which were once acceptable, but don’t make sense in today’s lab.

In this article the authors review the use of elevated temperatures in HPLC, and provide examples covering separations of both small molecules and biomolecules. Generic issues of temperature dependence of retention and plate height are discussed, and comparisons are made between temperature gradient and solvent gradient elution. They describe how the use of elevated temperatures allow good chromatographic efficiency to be obtained at flow-rates higher than those optimal at ambient temperature, thus increasing the speed of separation.

The guest authors describe the use of LC–MS for the analysis of peptides. They deal with peptide extraction, peptidomic analysis in organisms with and without genomic databases, identification of peptides with conserved N- and C- terminal sequences, and in situ MALDI-TOF peptide profiling.