Assessing Repeatability of a Peptide Mapping Method Using the ACQUITY Arc Bio System

Significance of the topic

Peptide mapping is a critical analytical tool for characterizing protein therapeutics, ensuring product quality, and detecting modifications. Modern UHPLC systems with biocompatible flow paths can enhance separation performance, resolution, and sensitivity compared to conventional HPLC, supporting robust method development and quality control in biopharmaceutical workflows.

Objectives and overview of the study

This work aims to demonstrate the repeatability of a peptide mapping protocol using the Waters ACQUITY Arc Bio System. By analyzing five consecutive injections of a tryptic digest of trastuzumab, the study evaluates retention time and peak area precision as indicators of system performance and data reliability.

Methodology

• A standard tryptic digest of trastuzumab was prepared.
• Separation was performed on an XBridge BEH C18 XP column (130 Å, 2.5 µm, 4.6 × 100 mm).
• A 60 minute acetonitrile gradient in TFA mobile phase was used.
• Five identical injections were run under consistent UHPLC conditions.
• Data processing and peak integration were conducted in Empower 3 software to eliminate operator bias.

Instrumentation

The analysis utilized the Waters ACQUITY Arc Bio System, a quaternary UHPLC platform featuring biocompatible flow paths, coupled with a Waters XBridge BEH C18 XP column. Empower 3 software facilitated batch processing and automated data handling.

Main results and discussion

Retention time repeatability was assessed for 102 peptide peaks across five injections. Most peaks exhibited a percent relative standard deviation (RSD) between 0.025 % and 0.05 %, fitting an approximate Gaussian distribution. Early‐eluting peptides showed slightly higher RSD values due to low retention factors. Peak area RSD was evaluated for eight representative peptides distributed throughout the gradient, with values ranging from 0.26 % to 0.93 %. These metrics confirm the system’s high precision for complex peptide separations.

Benefits and practical applications of the method

• High retention time and area precision support reliable peptide identification and quantification.
• Biocompatible UHPLC hardware reduces adsorption and carry-over for sensitive biomolecule analysis.
• Automated data processing minimizes user intervention and enhances reproducibility.
• The method suits quality control, method development, and lifecycle management in biopharmaceutical labs.

Future trends and potential applications

Advances in UHPLC column chemistry and mobile phase optimization may further improve early peak precision. Integration with high‐resolution mass spectrometry will enhance peptide characterization and impurity profiling. Emerging bioseparation platforms may adopt similar biocompatible designs to extend robustness to challenging conditions such as high salt and extreme pH.

Conclusion

The Waters ACQUITY Arc Bio System demonstrated excellent repeatability in peptide mapping assays, with retention time RSD below 0.05 % and peak area RSD under 1 %. These results underscore the system’s suitability for rigorous biopharmaceutical analysis, supporting consistent data generation and streamlined quality control workflows.

References

• ICH Q10 Pharmaceutical Quality System, International Conference on Harmonisation, June 2008.