Development of a Method for Multipesticide Analysis Using the Agilent 1260 Infinity Analytical SFC System with Triple Quadrupole MS Detection

Importance of the Topic

Supercritical fluid chromatography coupled with triple quadrupole mass spectrometry offers rapid, high-resolution separation of a wide range of pesticide residues in food matrices while significantly reducing solvent consumption and analysis times compared to conventional liquid chromatography approaches.

Objectives and Study Overview

The study aimed to develop and validate a single-run SFC–MS method capable of quantifying over 200 pesticide compounds in fruits and vegetables. Key objectives included optimizing chromatographic conditions on the Agilent 1260 Infinity Analytical SFC System, achieving low limits of quantitation, and evaluating method performance across different produce matrices.

Methodology and Instrumentation

Sample Preparation:

• QuEChERS extraction of homogenized fruits and vegetables with acetonitrile.
• Dispersive SPE cleanup using primary secondary amine sorbent and anhydrous MgSO4.
• Addition of formic acid to stabilize susceptible analytes.

Instrumentation Used:

• Agilent 1260 Infinity Analytical SFC System with CO2/methanol binary pump and backpressure regulator set at 120 bar.
• Agilent 6460 Triple Quadrupole LC/MS in positive electrospray mode using dynamic MRM acquisition.
• ZORBAX NH2 column (4.6 × 150 mm, 5 µm) with methanol/water (95:5) make-up flow containing ammonium formate and formic acid.

Main Results and Discussion

Chromatographic Performance:

• 223 of 254 pesticide standards eluted within 20 minutes; 195 compounds were eluted within 10 minutes using a gradient from 2 % to 10 % methanol.
• Retention time precision was better than 1 % RSD for 165 compounds; peak area precision was below 5 % RSD for 162 compounds.

Sensitivity and Linearity:

• Limits of quantitation were ≤ 1 ppb for 167 pesticides and 0.5 ppb for 102 compounds; all met regulatory criteria.
• Calibration curves showed linearity with R² ≥ 0.999 for all analytes.

Matrix Effects and Recoveries:

• Recovery rates in strawberry extracts at 10 ppb spike were within 70–120 % for 193 of 223 pesticides.
• Standard addition experiments revealed matrix suppression up to 30 %, highlighting the value of matrix-matched calibration or internal standards.

Real-Sample Examples:

• Triadimenol detected in tomato at 1.36 ppb (LOQ 0.1 ppb); boscalid in strawberry at 0.75 ppb near the LOD.
• Trifloxystrobin quantification in apple shifted from 8.1 ppb by external calibration to 11.3 ppb using standard addition.

Benefits and Practical Applications

The developed SFC–MS method enables high-throughput screening of multipesticide residues with reduced solvent usage and simplified workflows. Direct injection of acetonitrile extracts streamlines routine analyses in quality control and regulatory laboratories.

Future Trends and Applications

Emerging directions include:

• Coupling SFC with high-resolution mass spectrometry for non-targeted screening and improved compound identification.
• Automation of sample preparation and online extraction to further increase throughput.
• Development of advanced stationary phases to enhance selectivity for polar or structurally similar analytes.
• Application of machine learning algorithms for automated data processing and trend analysis in monitoring programs.

Conclusion

This work demonstrates a robust, sensitive, and rapid SFC–triple quadrupole MS approach for comprehensive multipesticide analysis in food products, delivering excellent chromatographic performance, low limits of quantitation, and reliable quantification in complex matrices.

References

1. Regulation (EC) No 396/2005 of the European Parliament and of the Council on maximum residue levels of pesticides in or on food and feed.
2. Naegele E. Analysis of Pesticides by Supercritical Fluid Chromatography/Mass Spectrometry – Optimizing the Agilent 1260 Infinity Analytical SFC System in Combination with the Agilent 6460 Triple Quadrupole LC/MS. Agilent Application Note 5991-5256EN, 2014.
3. Naegele E., Glauner T. Analysis of pesticides in vegetable samples with the Agilent 1260 Infinity Analytical SFC System with triple quadrupole MS detection. Agilent Application Note 5991-5443EN, 2015.
4. Anastassiades M., Lehotay S.J., Štajnbaher D., Schenck F.J. Fast and easy multiresidue method employing acetonitrile extraction/partitioning and dispersive solid-phase extraction for determination of pesticide residues in produce. Journal of AOAC International 86(2):412–431, 2003.
5. United States Environmental Protection Agency. Pesticide Fact Sheet: Boscalid. July 2006; updated December 11 2011.
6. European Commission. Health & Consumer Protection Directorate – Safety of the Food Chain: Guidance Document SANCO/12571/2013 on analytical quality control and validation procedures for pesticide residue analysis in food and feed.