Fast Analysis of Pesticide Residues in Food Samples Using GC/MS/MS

Importance of the topic

Rapid and reliable multiresidue analysis of pesticides in fruits and vegetables is essential for food safety monitoring, regulatory compliance, and laboratory efficiency. Shortening gas chromatography–mass spectrometry (GC/MS/MS) run times without compromising sensitivity or selectivity helps control laboratories meet rising sample throughput demands, reduce operating costs, and support public health initiatives.

Objectives and overview of the study

This Application Note evaluates and validates a 12.4-minute GC/MS/MS method for simultaneous determination of 203 pesticide residues in various fruit and vegetable matrices. Using an Agilent Intuvo 9000 gas chromatograph coupled to a 7010B triple quadrupole mass spectrometer, the method targets compounds recommended by the EURL for fruits and vegetables. Key goals included achieving a limit of quantitation (LOQ) of 2 µg/kg, ensuring robust performance across apple, orange, and tomato matrices, and demonstrating suitability for routine analysis and reference materials.

Methodology and instrumentation used

Sample preparation employs a modified citrate QuEChERS protocol:

• Weigh 10 g homogenized sample into a PTFE tube.
• Add 10 mL acetonitrile and 10 µL procedural standard mix (dichlorvos-D6, malathion-D10, triphenyl phosphate).
• Shake 4 min, add salts (MgSO₄, NaCl, citrate buffers), shake another 4 min, centrifuge.
• Evaporate 50 µL extract, reconstitute in ethyl acetate, add lindane-D6 injection standard.

Chromatographic separation and detection:

• Gas chromatograph: Agilent Intuvo 9000 with direct-contact heating and mid-column backflush chip.
• Columns: Two HP-5ms Ultra Inert (15 m × 0.25 mm, 0.25 µm film), flow rates 1.611 and 1.811 mL/min.
• Injector: Multimode Injector in pulsed splitless mode at 300 °C.
• Temperature program: 80 °C initial, 20 °C/min to 170 °C, then 20 °C/min to 310 °C (3.5 min hold).
• Detector: Agilent 7010B triple quadrupole MS in dynamic MRM with two transitions per analyte and 0.2 min time windows.

Main results and discussion

Linearity and sensitivity:

• Instrumental calibration from 1 to 200 µg/kg (R² > 0.99, residuals < 20%).
• 97% of compounds linear from 1 to 200 µg/kg in tomato; a few analytes required higher minimum levels.
• All pesticides identifiable at 1 µg/kg via two transitions with correct ion ratios.

Precision and accuracy:

• Recoveries between 70 % and 120 % for 97 % of compounds at 2, 10, and 50 µg/kg across three matrices.
• Instrumental repeatability RSD < 10 % at 2 and 5 µg/kg; method intraday/interday RSD < 20 % for 97 % of analytes.
• LOQ defined at 2 µg/kg for 97 % of pesticides, meeting EU quality control criteria.

Method application:

• Validated method applied to EUPT-FV18 (spinach) and EUPT-FV19 (lemon) proficiency test samples.
• Z-scores between –1.49 and +0.84 confirmed quantitative accuracy in routine reference materials.

Benefits and practical applications of the method

The fast 12.4-minute GC/MS/MS protocol delivers:

• ~1.5× faster analysis compared to conventional ovens, increasing daily sample throughput.
• Lower power consumption due to direct-contact heating.
• Maintained chromatographic resolution and robustness for routine QA/QC laboratories.
• Capability to meet stringent LOQs for baby food and other regulated products.

Future trends and possibilities of application

Advancements may include:

• Extension of direct-contact heating GC to broader classes of analytes (e.g., environmental contaminants, veterinary drugs).
• Integration with automated sample preparation and robotics for high-throughput workflows.
• Application of data-driven optimization and AI for dynamic MRM scheduling and instrument control.
• Coupling with hybrid detection systems (e.g., GC×GC-MS/MS) to further enhance separation and selectivity.

Conclusion

The validated 12.4‐minute GC/MS/MS method using Agilent Intuvo 9000 and 7010B instruments achieves rapid, sensitive, and reliable multiresidue pesticide analysis in fruits and vegetables. It meets EU validation criteria at low µg/kg levels while offering significant throughput and cost advantages for control laboratories.

Reference

1. Hakme E.; Uclés S.; Fernandez-Alba A.R. Further improvements in pesticide residue analysis in food by applying GC-QqQ-MS/MS technologies. Analytical and Bioanalytical Chemistry 2018, 410, 5491–5506.
2. European Commission DG-SANTE. Guidance document on analytical quality control and method validation procedures for pesticides residues analysis in food and feed, SANTE/11945/2015.
3. EU Pesticides Database. European Commission.
4. Anastassiades M.; Lehotay S.J.; Štajnbaher D.; Schenck F.J. Fast and easy multiresidue method using acetonitrile extraction/partitioning and dispersive solid-phase extraction for determination of pesticide residues in produce. Journal of AOAC International 2003, 86, 412–431.
5. Maštovská K.; Hajšlová J.; Lehotay S.J. Ruggedness and other performance characteristics of low-pressure GC-MS for fast analysis of multiple pesticide residues in food crops. Journal of Chromatography A 2004, 1054, 335–349.
6. Ferrer C.; Ruiz M.J.; García-Reyes J.F.; Molina-Díaz A.; Pérez R.A. European Union proficiency tests for pesticide residues in fruit and vegetables from 2009 to 2016: overview of results and achievements. Food Control 2017, 82, 101–113.