Multiresidue Pesticides Analysis in Norbixin Color Additive using LCMS-8050 and GCMS-TQ8040 NX

Significance of the Topic

Norbixin is a carotenoid-based color additive widely used in food, cosmetics, and pharmaceuticals. Its extraction from Bixa Orellana seeds can concentrate pesticide residues, posing food safety and regulatory compliance challenges. Monitoring pesticide contaminants at trace levels in such complex natural matrices is essential to protect human health and meet global quality standards.

Objectives and Study Overview

This study aimed to develop and validate a fast, sensitive, and robust method for simultaneous quantification of 72 pesticide residues in norbixin color additive. The approach integrates a modified QuEChERS extraction with ultra-fast triple quadrupole LC-MS/MS (LCMS-8050) and GC-MS/MS (GCMS-TQ8040 NX) instrumentation. Validation parameters—limit of quantitation (LOQ), recovery, repeatability, and reproducibility—were assessed against Standard Method Performance Requirements (SMPR).

Methodology

• Sample preparation employed a modified QuEChERS protocol using acetonitrile with sodium chloride and anhydrous magnesium sulfate for extraction.
• Dispersive solid-phase clean-up included C-18, graphitized carbon black (GCB), PSA, and magnesium sulfate to minimize matrix interferences.
• Post-clean-up extract was split: one portion diluted 40-fold in methanol:water (50:50) for LC-MS/MS, and another reconstituted in ethyl acetate (2.5-fold dilution) for GC-MS/MS.
• Matrix-matched calibration ranged from 0.05–10 µg/L for LC-MS/MS and 1–50 µg/L for GC-MS/MS, using external weighted regression (1/C2).
• Recovery and precision were evaluated at 5, 10, and 25 µg/kg spiking levels with six replicates each.

Used Instrumentation

• LCMS-8050 triple quadrupole mass spectrometer with Nexera X2 UHPLC and Shim-pack Scepter C18-120 column
• GCMS-TQ8040 NX triple quadrupole GC-MS with AOC-20i + s autosampler and SH-Rxi-5Sil MS column
• LabSolutions Insight software for data acquisition and validation parameter evaluation

Main Results and Discussion

• LC-MS/MS achieved LOQs of 5 µg/kg for all 72 pesticides; GC-MS/MS reached LOQs of 5 µg/kg for 45 compounds, 10 µg/kg for 10 compounds, and 25 µg/kg for one compound (THPI as Captan degrader).
• Linearity was excellent (R² ≥ 0.99) with accuracy between 80–120 % according to SANTE criteria.
• Recoveries mostly fell within 60–120 %; Methoxyfenozide exhibited 125 % recovery at 10 µg/kg, slightly above SMPR limits.
• Repeatability (RSDr) was below 20 %, and within-laboratory reproducibility (RSDR) below 30 % across all analytes.

Benefits and Practical Applications

• Enables comprehensive multi-residue pesticide screening in complex pigment matrices with high throughput.
• Reduces sample contamination and instrument maintenance through effective clean-up procedures.
• Facilitates rapid method setup using Shimadzu method packages and databases.
• Suitable for routine quality control in food, cosmetic, and pharmaceutical industries.

Future Trends and Potential Applications

• Extension of the protocol to other botanical extracts and natural colorants.
• Adoption of high-resolution mass spectrometry for non-target compound screening.
• Integration of on-line clean-up automation to further increase sample throughput.
• Implementation of advanced data analytics and AI-driven workflows for peak detection and quantitation.

Conclusion

The combined modified QuEChERS extraction with LCMS-8050 and GCMS-TQ8040 NX provides a validated, robust, and sensitive workflow for pesticide residue analysis in norbixin. It meets regulatory SMPR criteria, offering reliable trace-level quantitation and reproducible performance for high-throughput monitoring in QA/QC laboratories.

References

• 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.
• European Commission. Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticide Residues and Analysis in Food and Feed, SANTE/11312/2021.