Rapid Confirmation of the Purity of APIs Using the Agilent LC/MSD iQ Mass Selective Detector and WalkUp Software

Importance of topic

In pharmaceutical synthesis workflows, rapid and reliable purity assessment of active pharmaceutical ingredients (APIs) is crucial for process optimization and quality control. Traditional HPLC methods relying solely on UV detection can suffer from coelution issues, poor sensitivity for nonchromophoric compounds, and the need for external standards. Integration of mass detection into routine liquid chromatography provides an additional identification dimension, enabling more accurate and sensitive impurity profiling without extensive method development.

Objectives and overview of the study

This application note evaluates an open-access platform combining the Agilent InfinityLab LC/MSD iQ single-quadrupole mass detector with MassHunter WalkUp software for the rapid purity confirmation of 22 APIs. The goals were to demonstrate seamless integration with existing Agilent LC systems, verify the performance in detecting coeluting species and trace impurities, and streamline sample submission and reporting in a multiuser environment.

Methods and instrumentation

The study employed an Agilent 1290 Infinity II LC system configured with a Poroshell 120 EC-C18 column (2.1×50 mm, 1.9 μm) and a rapid gradient from 5 % to 90 % acetonitrile with 0.1 % formic acid at 0.8 mL/min. Samples of APIs at 10 μg/mL were analyzed using both diode-array UV detection (254 nm and reference 360 nm) and the InfinityLab LC/MSD iQ operated in Auto Acquire mode (scan m/z 100-1000, positive and negative ESI). Sample submission and data acquisition were managed via MassHunter WalkUp, while Agilent OpenLab CDS provided automated data processing, purity assessment by TIC %, and report generation.

Used instrumentation

• Agilent 1290 Infinity II High Speed Pump, Vialsampler, Multicolumn Thermostat, Diode Array Detector
• Agilent InfinityLab LC/MSD iQ single-quadrupole mass selective detector
• MassHunter WalkUp open-access software and OpenLab CDS for acquisition and sample purity workflows

Main results and discussion

Mass detection enabled clear discrimination of coeluting peaks and identification of impurities absent or ambiguous in UV traces. For example, erythromycin, which has weak UV absorption, was effectively confirmed by its nominal mass (m/z 733) and impurities were resolved in the MS chromatogram. A simulated degradation study of captopril revealed formation of a disulfide dimer (m/z 433) after three months at room temperature, reducing purity from 100 % to 58.5 %; this transformation was unambiguously detected by MS. A multi-API sequence showed automatic flagging of impure samples below preset purity thresholds, illustrating robust open-access performance.

Benefits and practical applications

Combining UV and mass detection accelerates impurity screening, avoids external standards for retention time confirmation, and enhances sensitivity for trace components up to two orders of magnitude below UV-only limits. The open-access WalkUp interface reduces training requirements, allows controlled sample submission, and delivers automated reports to users, promoting high throughput in pharmaceutical and biopharma quality-control labs.

Future trends and possibilities

Further developments may include expanded adduct monitoring, integration of high-resolution MS capabilities for detailed structural elucidation, and cloud-based data sharing to support decentralized labs. Automated degradation and stability studies could leverage AI-driven chromatogram interpretation for predictive impurity profiling.

Conclusion

The Agilent InfinityLab LC/MSD iQ with MassHunter WalkUp offers a user-friendly, open-access solution for rapid API purity assessment, combining robust chromatographic separation, sensitive mass confirmation, and streamlined workflows. This approach improves decision-making speed and reliability in pharmaceutical development.