High Throughput Target and Suspect Pesticide Analysis using a new LC/Q-TOF Screener Software

Importance of the Topic

The continual expansion of regulated pesticides in food safety testing demands analytical solutions that combine wide analyte coverage, high throughput, and reliable quantitation. Integrating targeted and suspect screening reduces time and cost while maintaining compliance with maximum residue level (MRL) regulations.

Study Objectives and Overview

This work demonstrates a unified workflow for simultaneous quantitation and suspect screening of nearly 400 pesticides across diverse food matrices using the Agilent 6546 LC/Q-TOF coupled with MassHunter Quantitative Analysis 10.0 and its new LC/Q-TOF Screener tool.

Methodology and Instrumentation

Samples of organic black tea, strawberry, avocado, and broccoli were extracted via QuEChERS EN kits and spiked at five concentration levels (5–100 ppb). Reverse-phase chromatography was performed on a 1290 Infinity II UPLC, followed by All Ions non-targeted acquisition at 6 Hz on the Agilent 6546 LC/Q-TOF. Data were converted with the SureMass profile-based algorithm and processed using a method built from a Personal Compound Database and Library (PCDL) with predefined precursor, fragment, isotope, and adduct patterns.

Key Results and Discussion

• Mass accuracy remained within 2 ppm for most targets (all <5 ppm), conforming to SANTE guidelines.
• High-resolution data (30,000 at m/z 118) and a dynamic range of 10⁵ ensured reliable detection across concentrations.
• Linearity of R² > 0.99 and precision (RSD < 20%) were achieved at the 5 ppb limit of quantitation in each matrix.
• The LC/Q-TOF Screener interface rapidly flags confirmed and suspect compounds based on outlier thresholds for mass accuracy, retention time, qualifier ions, and isotope pattern, reducing manual review workload.
• In 16 unknown conventional strawberry samples, the majority of detected analytes were targets, quantified directly; a few suspects were highlighted for further confirmation or retrospective analysis without reinjection.

Practical Benefits and Applications

The combined method allows laboratories to:

• Quantify and screen hundreds of pesticides in a single run.
• Maintain confidence in identification using qualifier ions and pattern matching.
• Reduce review burden through automated suspect flagging.
• Perform retrospective screening for newly regulated compounds without repeat analysis.

Future Trends and Opportunities

Expanding suspect libraries, implementing automated data mining, and integrating machine learning algorithms could further accelerate high-throughput screening. Enhanced sample preparation and multiplexed workflows may extend this approach to more complex matrices and broader contaminant classes.

Conclusion

The Agilent 6546 LC/Q-TOF combined with MassHunter Quantitative Analysis and the LC/Q-TOF Screener tool provides an efficient, accurate, and scalable solution for simultaneous targeted quantitation and suspect screening of large pesticide panels, meeting rigorous regulatory requirements while minimizing labor and cost.

References

1. Guidance document on analytical quality control and method validation procedures for pesticide residues and analysis in food and feed, SANTE/11813/2017, 21–22 November 2017.