Application robustness of the 6495 triple quadrupole LC/MS system for non-stop Pesticide analysis in black tea matrix

Application Robustness of the 6495 Triple Quadrupole LC/MS System for Nonstop Pesticide Analysis in Black Tea Matrix

Importance of the Topic

Robust separation and detection of pesticide residues in agricultural products such as black tea are critical for quality control and regulatory compliance. High throughput laboratories require instrumentation that can operate without interruption over extended periods while maintaining sensitivity and reproducibility.

Study Objectives and Overview

This study evaluated the operational stability and analytical performance of the Agilent 6495 triple quadrupole LC MS during continuous pesticide analysis in a complex black tea matrix. Key goals included assessing signal consistency over 2000 targeted MRM injections, monitoring maintenance events, and verifying negative mode sensitivity.

Methodology and Instrumentation

• Sample Preparation: Black tea steeped in room temperature water for two hours followed by QuEChERS extraction with Agilent EN salt and dispersive SPE to remove pigments. Extracts were filtered and fortified with pesticide mix and stable isotope standards.
• LC MS Conditions: Analysis performed on an Agilent 1290 Infinity LC with Poroshell C18 guard and Eclipse Plus RRHD column at 30 °C. Mobile phases were water and methanol each containing 5 mM ammonium formate and 0.1% formic acid. A gradient elution at 0.6 mL per minute and 2 microliter injection volume was used.
• Mass Spectrometry: The 6495 system equipped with VacShield technology for rapid maintenance and iFunnel ion compression for enhanced sensitivity. MRM transitions were monitored with sub millisecond dwell times. A Jet Stream source provided optimized gas flows and voltages.

Main Results and Discussion

The instrument completed 2000 pesticide sample injections, 400 blanks, and 200 calibration and full scans over 16 days without maintenance. Raw peak area RSD values for pyraclostrobin, atrazine, diazinon, and dimethoate were below 10 percent. Corrected areas using internal standards further reduced variability. The iFunnel design tolerated visible matrix deposition without signal interference. A negative mode check confirmed a 1 fg on column detection limit for chloramphenicol with RSD near 14 percent.

Practical Benefits and Applications

Continuous operation without downtime demonstrates suitability for high throughput food safety testing. Low variability supports reliable quantitative results in QA QC laboratories. The fast maintenance provided by VacShield reduces labor and preserves uptime.

Future Trends and Opportunities

Integrating real time instrument health monitoring with automated maintenance scheduling can further extend operation. Expanding the application to other challenging matrices such as herbal extracts or environmental samples will validate broader utility. Advances in ion funnel technology promise increased sensitivity for ultratrace analysis.

Conclusion

The Agilent 6495 triple quadrupole LC MS system demonstrated high robustness, sensitivity, and reproducibility during nonstop pesticide analysis in a complex tea matrix. It delivered consistent results over extended runs with minimal maintenance, making it a valuable tool for routine analytical workflows.

References

• Routine Multiresidue Pesticide Analysis using the Agilent 6470 Triple Quadrupole Mass Spectrometer 5991 6357EN
• Agilent ASMS 2023 Poster Reprint DE56468839 May 31 2023