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

Importance of the Topic

The quantitative analysis of pesticide residues in natural color additives, such as norbixin from annatto, is critical for food safety and regulatory compliance. Complex matrices like carotenoid-rich oleoresins can concentrate agrochemical residues, posing health risks. Robust, sensitive analytical protocols enable producers and quality control laboratories to monitor trace-level contaminants and meet international safety standards.

Study Objectives and Overview

This work aimed to develop and validate a unified extraction and analysis approach for 72 commonly observed pesticides in norbixin color additive. By combining a modified QuEChERS sample preparation with triple-quadrupole LC-MS/MS and GC-MS/MS methods, the study evaluated limits of quantitation (LOQ), linearity, recovery, repeatability (RSDr), and reproducibility (RSDR) against Standard Method Performance Requirements (SMPR).

Methodology and Instrumentation

A single modified QuEChERS protocol using acetonitrile extraction and salt partitioning (NaCl and MgSO4) was applied. Clean-up utilized C-18, graphitized carbon black, PSA sorbents, and MgSO4 to reduce matrix interferences. Extracts were split for LC-MS/MS and GC-MS/MS:

• LC-MS/MS analysis on Shimadzu LCMS-8050 coupled with Nexera X2 UHPLC, using a C18 column and ammonium formate/formic acid gradient.
• GC-MS/MS analysis on Shimadzu GCMS-TQ8040 NX with a 5% phenyl methylpolysiloxane column under splitless injection and helium carrier gas.

Used Instrumentation

• Shimadzu LCMS-8050 with Nexera X2 SIL-30AC autosampler
• Shimadzu GCMS-TQ8040 NX with AOC-20i+s auto-injector
• LabSolutions Insight software for data processing

Results and Discussion

Matrix-matched calibration curves demonstrated excellent linearity (R² ≥ 0.99) over 0.05–10 μg/L (LC-MS/MS) and 1–50 μg/L (GC-MS/MS). On LC-MS/MS, all 72 pesticides achieved LOQs of 5 μg/kg with recoveries between 60–120% and RSDr ≤ ±20%, RSDR ≤ ±30%. On GC-MS/MS, 45 compounds met 5 μg/kg LOQ, 10 at 10 μg/kg, and 1 at 25 μg/kg. Methoxyfenozide showed slight over-recovery. Captan was monitored via its degradant THPI.

Benefits and Practical Applications

• Single extraction platform reduces sample handling and solvent usage.
• High sensitivity enables trace-level pesticide monitoring in challenging matrices.
• Validated performance supports regulatory compliance and routine QA/QC in food, cosmetics, and pharmaceutical industries.

Future Trends and Opportunities

Advancements in high-resolution mass spectrometry, automated sample preparation, and expanded pesticide libraries will further enhance throughput and compound coverage. Integration of AI-driven data analysis can streamline method optimization and anomaly detection. Portable MS technologies may enable on-site screening of color additives in supply chains.

Conclusion

The described QuEChERS combined LC-MS/MS and GC-MS/MS workflow provides a reliable, efficient, and sensitive tool for multiresidue pesticide analysis in norbixin. Shimadzu’s ultra-fast instrumentation and tailored databases ensure robust quantitation at low μg/kg levels, supporting safety assurance in natural color additives.

References

1. Anastassiades M, Lehotay SJ, Štajnbaher D, Schenck FJ. 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. 2003;86:412–431.
2. European Commission. Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticide Residues and Analysis in Food and Feed. SANTE/11312/2021.