Analysis of residual pesticides in Carrot Oleoresin using GCMS-TQ8040 NX and LCMS-8045

Importance of the Topic

Carrot oleoresin is widely used as a natural colorant in food, cosmetics, nutraceuticals and pharmaceuticals. During its solvent‐based or steam‐distillation extraction, pesticide residues from raw carrots become highly concentrated in the oleoresin matrix. Reliable determination of these residues at trace levels is essential for safety, regulatory compliance and quality control in industrial and research laboratories.

Objectives and Study Overview

This study aimed to develop and validate a robust, high‐throughput method for simultaneous quantification of 72 pesticide residues in complex carrot‐oleoresin. It combined a modified QuEChERS extraction with dual analysis by GC‐MS/MS (triple quadrupole) and LC‐MS/MS, assessing sensitivity (LOQ), linearity, recovery, repeatability and reproducibility.

Methodology and Used Instrumentation

A single modified QuEChERS procedure was employed:

• Extraction with acetonitrile and optimized proportions of NaCl and MgSO4
• Cleanup using C18, graphitized carbon black (GCB), primary secondary amine (PSA) and MgSO4
• Partition and reconstitution: ethyl acetate for GC‐MS/MS and methanol/water (70:30, v/v) for LC‐MS/MS

Instrumentation:

• GC‐MS/MS: Shimadzu GCMS‐TQ8040 NX with AOC‐20i autosampler, SH-Rxi-5Sil MS column
• LC‐MS/MS: Shimadzu LCMS-8045 with Nexera X2 front end, Shim-pack™ Scepter column
• Smart Pesticides Database Ver.2 and LCMS Method Package Ver.3 for rapid MRM optimization
• LabSolutions Insight software for data processing and validation evaluation

Main Results and Discussion

Linearity was established over 1–200 μg/L (GC‐MS/MS) and 0.5–100 μg/L (LC‐MS/MS) with R² > 0.98 for most analytes. LOQs of 10 μg/kg were achieved for 66 compounds on both systems (25 μg/kg for flonicamid on LC‐MS/MS). Recovery rates at LOQ levels ranged 60–120%, meeting SMPR criteria. Repeatability (n = 6) showed RSDr ≤ 20%, and reproducibility (n = 7) RSDR ≤ 30%. Two pesticides (etoxazole, chlorfenapyr) did not meet recovery criteria, while captan and THPI were undetectable due to matrix interference. The modified QuEChERS effectively reduced matrix effects and instrument contamination.

Benefits and Practical Applications

• High sensitivity and selectivity for diverse pesticides in a challenging matrix
• Dual GC‐MS/MS and LC‐MS/MS workflows allow selection based on analyte properties and LOQ requirements
• Reduced sample preparation time and solvent use through a single extraction protocol
• Enhanced throughput via Shimadzu method packages and software tools

Future Trends and Potential Uses

Integration of automated sample preparation and real‐time data analytics could further improve throughput and data quality. Expanding the database to include emerging pesticides and degradants will address evolving regulatory needs. Coupling with high‐resolution MS may enhance identification of unknown contaminants in oleoresin and other complex botanical extracts.

Conclusion

The combined modified QuEChERS, GC‐MS/MS and LC‐MS/MS method provides a sensitive, reproducible and efficient approach for monitoring pesticide residues in carrot oleoresin. It supports regulatory compliance and quality assurance in food and related industries.

References

1. 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 the Determination of Pesticide Residues in Produce. J. AOAC Int. 86 (2003) 412–431.
2. European Commission. Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticide Residues Analysis in Food and Feed. SANTE/12682/2019.