Characterizing buffer exchange in automated peptide mapping sample preparation of biotherapeutics.

Multi-attribute methods are crucial for characterizing antibody-based biotherapeutics throughout their development, providing insights into post-translational modifications. Although LC-MS peptide mapping is effective, it often suffers from long sample preparation times, limiting throughput. To address this, modern automated workflows with liquid handlers have been developed to increase efficiency by reducing MS sampling downtime and manual work. Desalting/buffer-exchange steps are vital as they carry potential for sample loss and can affect enzymatic activities. This study compares multiple buffer exchange tips from semi-automated centrifugal options to fully automated gravity- and positive pressure-driven options. By analyzing these tips for performance, robustness, and recovery across a variety of biotherapeutic modalities, we aim to enhance the robustness of automated peptide mapping workflows.