Automated Peak Tracking Using Mass Detection and Fusion QbD Software

Significance of the Topic

This application note illustrates the growing need for reliable peak tracking in chromatographic method development. By combining photodiode array and mass detection with advanced software tools, laboratories can accelerate method optimization, ensure accurate identification of related compounds, and build robust Quality by Design workflows.

Objectives and Study Overview

The primary goal was to demonstrate automated peak tracking during UPLC method development for formoterol, budesonide, and their related impurities. The study integrates ACQUITY UPLC PDA and QDa mass detection data within the Fusion QbD platform to streamline chromatographic screening, optimization, and design space construction.

Methodology and Instrumentation

The experimental workflow comprised:

• Preparation of a test mixture containing budesonide, formoterol fumarate, and three related impurities at defined concentrations in 70/30 water/acetonitrile.
• Gradient elution on an ACQUITY UPLC H-Class PLUS system using a BEH C18 1.7 µm, 2.1 × 100 mm column with variable temperature (30–50 °C) and a quaternary solvent manager selecting among three ammonium acetate/ ammonium hydroxide buffers (pH 8.0–9.0).
• Detection by ACQUITY UPLC PDA at 244 nm and ACQUITY QDa Mass Detector in ESI+ mode (capillary voltage 0.8 kV, cone voltage 15 V, source temperature 600 °C).
• Data acquisition and processing using Empower 3 CDS and Fusion QbD (Release 9.9) for design of experiments, peak tracking, and design space modeling.

Main Results and Discussion

Auto-Deconvolution of Coeluted Peaks
PeakTracker successfully identified and recovered retention time and resolution data for fully coeluted peaks by leveraging combined UV and MS spectra. Two impurity peaks (B and C) that were unresolved by UV detection alone were automatically deconvoluted, improving model accuracy.

Automated Peak Tracking
The software automatically mapped compound identities across all chromatograms despite shifts in retention or elution order. Spectral overlays and manual editing tools ensured correct assignments for isomeric or epimeric species when UV and MS profiles were highly similar.

Resolution Mapping (Rs-Map)
Fusion QbD imported chromatographic responses (retention time, tailing factor, resolution, signal-to-noise) and generated 2D and 3D contour and overlay plots of predicted resolutions. Dynamic thresholding highlighted regions of the design space where all peaks met the minimum USP resolution of 1.5 and the formoterol tailing factor requirement, enabling rapid selection of optimal conditions.

Benefits and Practical Applications

• Enhanced confidence in peak identification through fusion of UV and MS data.
• Reduced manual intervention in method development, speeding up throughput.
• Improved accuracy of design space models by filling missing data for hidden peaks.
• Graphical tools for dynamic evaluation of chromatographic performance across multiple factors.

Future Trends and Applications

Integration of artificial intelligence algorithms for predictive chromatographic optimization may further automate design space creation. Expansion to additional detectors (e.g., high-resolution MS) and coupling with real-time PAT tools could enable fully automated end-to-end QbD workflows in pharmaceutical and environmental analytics.

Conclusion

This study highlights how the PeakTracker technology within Fusion QbD, combined with ACQUITY UPLC PDA and QDa detectors, provides a powerful solution for automated peak tracking and robust method development. It simplifies deconvolution of coeluted peaks, ensures accurate mapping of compound identities, and accelerates construction of reliable design spaces.

References

1. F.L. Alkhateeb, P. Rainville. Applying a Software-Assisted Analytical Quality-by-Design Approach for the Analysis of Formoterol, Budesonide, and Related Compounds by UPLC-MS. Application Note, Waters Corporation, August 2019, 720006654EN.