Fast and Ultrafast LC-MS/MS Methods for Robust and Reliable Analysis of Pesticides in Food Using the Vanquish UHPLC System

Importance of the Topic

Liquid chromatography–tandem mass spectrometry is indispensable for monitoring trace pesticide residues in food to protect human health. Regulatory limits at ppb levels demand methods that balance sensitivity, speed, and reproducibility. Fast and ultrafast UHPLC separations with timed SRM enhance throughput and data quality for high‐volume testing laboratories.

Study Objectives and Overview

This work compares a 15 min “fast” UHPLC-MS/MS method with an ultrafast 5 min approach for quantifying over 250 pesticides in strawberry, leek, and wheat flour extracts. It demonstrates straightforward method transfer from a legacy RSLC system to a modern Vanquish UHPLC platform and evaluates retention time stability, sensitivity, accuracy, and sample throughput.

Methodology and Instrumentation

Sample Preparation employed QuEChERS extraction of 10 g homogenized matrices with acetonitrile and water. Matrix‐matched standards at 5, 10, and 100 µg/L were used to assess performance at regulatory levels.

Instrumentation

• Thermo Scientific Vanquish UHPLC System (System Base, Binary Pump, Split Sampler HT, Column Compartment)
• Thermo Scientific TSQ Endura Triple Quadrupole MS with heated ESI source
• Chromeleon 7.2 CDS for data acquisition and processing

Chromatography used an Accucore aQ column (100×2.1 mm, 2.6 µm) with water/methanol gradients containing 5 mM ammonium formate and 0.1% formic acid. Flow rates of 0.3 mL/min (15 min method) and 0.9 mL/min (5 min method) were applied.

Results and Discussion

Method transfer required only a 0.32 min initial isocratic hold to align gradient delays, yielding retention time shifts under 5 s. Ultrafast separation increased throughput by 300% and reduced analysis time by 67%. SRM windows were narrowed from 30 s to 9 s and cycle times from 0.5 s to 0.34 s, preserving 10–15 data points per peak. Run‐to‐run and matrix‐to‐matrix retention time precision showed SDs below 0.30 s and 0.15 s, respectively. Validation criteria (accuracy 80–120%, RSD ≤ 15%, linearity) were met in all matrices for both methods.

Benefits and Practical Applications

• High throughput: 5 min runs accelerate large sample batches
• Robust quantitation: narrow SRM windows supported by stable retention times
• Regulatory compliance: meets ppb‐level sensitivity and precision
• Resource efficiency: reduced solvent use and instrument time

Future Trends and Potential Uses

Emerging directions include microflow UHPLC, AI‐driven dynamic SRM scheduling, and coupling with high‐resolution MS for broader screening. Automated sample preparation and cloud‐based data analytics will further streamline workflows and enhance decision support.

Conclusion

The ultrafast UHPLC-MS/MS workflow on the Vanquish/TSQ Endura platform delivers reliable pesticide quantitation with greatly increased throughput and uncompromised data quality, offering an efficient solution for modern food safety testing laboratories.

References

• Picó Y, Blasco C, Font G. Mass Spectrom Rev. 2004;23:45–85.
• Wang J et al. Thermo Fisher Scientific Poster Note PN-64106-ASMS-EN-0614S.
• Thermo Fisher Scientific. Product Spotlight: Solvent Delivery Technology and Peak Confidence. 2015.
• Carsten P et al. Thermo Fisher Scientific Poster Note PN-71518-EN-0215S.