Nitrosamines Analysis with LC/MS-MS

Importance of Nitrosamine Analysis

Nitrosamines are mutagenic impurities that pose a potential carcinogenic risk when present above strict thresholds in pharmaceutical products. Recent recalls of widely used drugs due to nitrosamine contamination have underscored the need for robust monitoring. Sensitive analytical workflows help manufacturers ensure patient safety and regulatory compliance while maintaining product quality.

Objectives and Study Overview

This work outlines a comprehensive approach to develop, validate, and implement LC‐MS/MS methods for trace‐level nitrosamine detection in active pharmaceutical ingredients (APIs) and finished drug products. Key aims include establishing sample preparation strategies, optimizing chromatographic separation, demonstrating mass spectrometry sensitivity, and aligning workflows with evolving regulatory guidelines.

Methodology and Instrumentation

A risk‐based method development was employed to achieve quantification at or below parts‐per‐billion levels. Sample preparation approaches ranged from simple dilution to solid‐phase extraction to remove matrix interferences and concentrate nitrosamines. Chromatographic separation on UPLC columns was tuned to divert the main API peak to waste while directing low‐level impurities to the MS detector. Tandem quadrupole mass spectrometry provided the sensitivity and selectivity required, using multiple reaction monitoring (MRM) transitions tailored to each nitrosamine species.

Used Instrumentation

• High‐performance UPLC system with MaxPeak surface technology for improved analyte recovery
• Tandem quadrupole mass spectrometers: Xevo Cronos, Xevo TQ‐S micro, and Xevo TQ Absolute for varying sensitivity needs
• Automated sample preparation platform (Andrew+) with compliance-ready OneLab software
• MassLynx Security software for method control and regulatory audit support

Major Results and Discussion

Optimized LC/MS/MS methods achieved detection limits below current regulatory thresholds for both simple nitrosamines (e.g., NDMA, NMBA) and complex nitrosamine drug substance related impurities (NDSRIs). Chromatographic conditions effectively separated nitrosamines from high‐abundance APIs, reducing ion suppression and source contamination. Deployment of APCI and ESI ionization modes enabled flexible analysis across a broad chemical space. Method validation demonstrated consistent accuracy, precision, and reproducibility within and between laboratories.

Benefits and Practical Applications of the Method

• High sensitivity and specificity meeting or exceeding regulatory requirements
• Adaptable workflows for different APIs, formulations, and impurity profiles
• Automated preparation and data acquisition improving throughput and reproducibility
• Regulatory readiness through harmonized method validation and secure software platforms

Future Trends and Applications

As regulatory agencies expand control to new mutagenic and genotoxic impurities, laboratories will require even greater sensitivity, flexibility, and automation. Emerging high‐resolution MS, hybrid ionization sources, and machine‐learning–driven data analysis will support faster method development and comprehensive impurity profiling. Integration of real‐time risk assessment tools may further streamline compliance and accelerate drug development.

Conclusion

LC‐MS/MS–based workflows offer a robust and future‐proofed solution for trace‐level nitrosamine quantification. By combining optimized sample preparation, tailored chromatographic strategies, and sensitive tandem mass spectrometry, laboratories can meet current and anticipated regulatory demands, ensuring the consistent safety and quality of pharmaceutical products.

References

No specific literature citations were provided in the source document.