QUALITY CONTROL ASPECTS OF REIMS TECHNOLOGY

Significance of the Topic

Rapid Evaporative Ionization Mass Spectrometry (REIMS) enables direct, preparation-free analysis of complex biological and food samples, offering rapid chemical profiling. Despite its practical benefits, standardized quality control (QC) procedures have been lacking, hindering method reliability and inter-laboratory comparability.

Objectives and Overview of the Study

The study aimed to develop and validate a QC application and reference materials for REIMS. Key goals included establishing system suitability testing criteria and evaluating long-term reproducibility across diverse REIMS ion sources and sample types over 2.5 years.

Methodology

Study design included:

• QC Materials: Mixtures of four phosphatidylglycerol standards (DPPG, POPG, DOPG, DSPG) in liquid and agarose matrices.
• Biological Samples: Certified bovine meat homogenates and cocoa chocolate (75% & 90% cocoa).
• Ablation Sources: OPO laser, CO2 laser, electrosurgical iKnife probe, and custom RF generators.
• Automation: Robotic handling to minimize operator variability.

Data acquisition involved a Waters Xevo G2-XS ToF mass spectrometer in negative ion mode (m/z 50–1200), with leucine enkephalin lockmass. QC criteria comprised peak presence and ratio checks, signal-to-noise thresholds, resolution assessment, and multivariate cross-validation (PCA, LDA). Long-term performance was tracked via relative standard deviation of PG intensity ratios and classification accuracy.

Instrumentation Used

• Waters Xevo G2-XS ToF Mass Spectrometer
• OPO and CO2 Laser Ablation Systems
• Electrosurgical iKnife Probe
• Custom Radiofrequency (RF) Generators (miniature and surgical)
• Venturi and Direct-T REIMS Inlets
• Robotic Sample Handling Platform

Main Results and Discussion

The QC application reliably flagged system suitability, achieving relative standard deviations below 10% for consolidated PG intensity ratios over two months. Long-term reproducibility exceeded 97% classification accuracy for meat and chocolate matrices. Stress tests altering detector voltage and resolution parameters confirmed the sensitivity of the QC metrics to instrument performance shifts.

Benefits and Practical Applications

• Routine QC monitoring enhances data consistency and comparability across REIMS deployments.
• Standardized reference materials and software allow early detection of instrument drift.
• Applicable to research, quality assurance, and industrial analytics involving rapid molecular profiling.

Future Trends and Potential Applications

Advancements may include expanding QC standards to additional lipid classes, integrating real-time feedback and cloud-based monitoring, applying machine learning for anomaly detection, and extending QC protocols to positive ion mode and novel REIMS configurations.

Conclusion

The developed QC workflow and reference materials establish a robust system suitability test for REIMS, ensuring long-term performance stability and fostering broader method adoption in diverse analytical settings.

References

No formal literature references were provided in the source document.