Reversed-Phase LC-MS Analysis Of Low-Abundance Impurities In A GLP-1a Therapeutic Using A Charged Surface 230Å Superficially Porous Phenyl-Hexyl Column

By Stephan M. Koza, Stephen J. Shiner, and Matthew A. Lauber

Achieving high-resolution purity analysis of tirzepatide requires chromatographic selectivity and sensitive characterization of low-abundance impurities. Reversed-phase LC methods paired with high-resolution mass spectrometry demonstrate how phenyl-hexyl selectivity, wide-pore superficially porous particles, and low-interaction column hardware can support detailed lipopeptide analysis. Acetonitrile gradients using either formic acid or trifluoroacetic acid enable impurity profiling and mass identification, while comparisons with an alternative charged-surface column reveal important differences in separation performance. Several synthesized impurity standards further illustrate the method’s resolving capabilities.

With analysis times of 46 minutes or less, see how these approaches provide a practical starting point for tirzepatide purity assessment, along with opportunities to tailor gradient conditions for faster analysis or improved resolution.