Screening Workflow for Extractables Testing Using the UNIFI Scientific Information System

Importance of the Topic

The analysis of extractable and leachable compounds from packaging and related materials is vital due to tightening global regulations. Rapid and reliable identification of both known and unknown contaminants ensures product safety and regulatory compliance.

Objectives and Study Overview

This application note describes a comprehensive screening workflow implemented in the Waters UNIFI Scientific Information System. The key aims are to integrate targeted screening, non-targeted data acquisition, multivariate statistical analysis, structural elucidation, and reporting into a single software environment to improve efficiency and confidence in extractables testing.

Methodology and Instrumentation

The workflow combines high-resolution mass spectrometry techniques:

• Quadrupole time-of-flight mass spectrometry (QTof) operated in MSE mode to acquire both low-energy precursor and high-energy fragment ion data in a single run
• Ion mobility QTof (IMS-QTof) for HDMSE providing an additional separation dimension based on collisional cross section values

Sample separations prior to MS include:

• UltraPerformance liquid chromatography (UPLC)
• Atmospheric pressure gas chromatography (APGC)
• Convergence chromatography (UPC2)

The UNIFI platform facilitates creation of a scientific library containing compound names, formulas, structures, fragmentation data, and ion mobility cross sections. Processing parameters such as mass accuracy, retention time tolerances, isotope matching, and CCS deltas are user-defined.

Key Findings and Discussion

Targeted screening against the scientific library efficiently identifies known compounds. Non-targeted screening with MSE/HDMSE generates comprehensive precursor–fragment datasets, enabling discovery of unexpected extractables. Comparative tools include:

• Binary Compare for pairwise sample vs blank evaluation, highlighting unique, common, or blank-specific features via mirrored chromatograms and mass tables
• Multivariate statistics with PCA, PLS-DA, and OPLS-DA for group comparisons, marker selection, and trend plotting

The Discovery tool integrates accurate mass, isotope patterns, and fragmentation to rank elemental compositions and search structural databases for compound candidates. Analysts can assign identities, update the scientific library, and quantify targets using calibration curves.

Benefits and Practical Applications

The integrated UNIFI workflow reduces manual data processing and expert intervention, accelerates decision making, and enhances confidence in both targeted and non-targeted extractables analysis. It is applicable to cosmetics, 3D printing media, food, and pharmaceutical packaging assessments.

Future Trends and Potential Applications

Ongoing developments may include expanded spectral and mobility libraries, machine-learning algorithms for automated feature annotation, and real-time dashboard reporting. Integration with additional regulatory databases and enhanced chemometric modules will further streamline compliance workflows.

Conclusion

The UNIFI Scientific Information System delivers a unified, automated approach for extractables screening, combining targeted and non-targeted strategies, multivariate statistics, and structural elucidation. This approach meets current regulatory demands and sets the stage for advanced data-driven analytics in material safety evaluation.

References

1. McCullagh M, Hanot V, Goscinny S. Use of Ion Mobility Spectral Cleanup and Collision Cross Section Values to Increase Confidence and Efficiency in Pesticide Residues Screening Strategies. Waters application note 720005080en. 2014.
2. Čabovska B. Non-targeted screening analysis of packaging extracts using the UNIFI Scientific Information System. Waters application note 720005326en. 2015.