Determination of Over 300 Pesticides in Cinnamon

Significance of the Topic

Cinnamon is a globally consumed spice and medicinal ingredient that often carries complex matrices enriched in pigments, essential oils and fatty compounds. Cultivation and storage practices frequently involve multiple pesticide applications, raising food safety concerns and regulatory compliance challenges. Reliable, high-throughput analytical methods are essential to monitor hundreds of pesticide residues in cinnamon powder, ensuring consumer protection and adhering to international standards.

Objectives and Study Overview

This application note describes the development and optimization of a multi-residue analysis for more than 300 pesticides in cinnamon bark powder. The primary objectives were to achieve efficient extraction, selective removal of matrix interferences and sensitive detection by combining a modified QuEChERS AOAC extraction, passthrough cleanup using Captiva EMR–GPD cartridges and dual detection via LC/MS/MS and GC/MS/MS. Method performance was evaluated in terms of recovery, precision, matrix effect, calibration linearity and limits of quantitation in a challenging cinnamon matrix.

Methodology

Sample Preparation

• Weigh 1.5 g of cinnamon powder and add 4 mL of water containing 0.1% formic acid to hydrate the matrix.
• Extract with acetonitrile (ACN) using the Agilent Bond Elut QuEChERS AOAC kit and shake with salts and ceramic beads.
• Collect 2.7 mL of crude extract, mix with 0.3 mL water, and load directly onto Captiva EMR–GPD cartridges for passthrough cleanup under gravity or low pressure.
• Dry eluate with anhydrous MgSO4, centrifuge and dilute the supernatant for GC/MS/MS (undiluted) and LC/MS/MS (5× dilution).

Cleanup Optimization

• Evaluated water premixing ratios (0%, 5%, 10%) with crude extract before EMR–GPD cleanup to balance matrix removal and analyte recovery.
• A 10% water premix provided optimal recoveries for sensitive pesticides without compromising cleanup efficiency.

Calibration and Quantitation

• Matrix-matched calibration standards spanned 5–5 000 ng/g in cinnamon, corresponding to 0.5–500 ng/mL in final extract.
• Quantitation employed dynamic multiple reaction monitoring (dMRM) with 1/x²-weighted linear or quadratic regression for each compound.
• Quality controls at 10 and 100 ng/g assessed recovery, reproducibility and matrix effects following SANTE/11312/2021 guidelines.

Instrumentation Used

Liquid Chromatography–Tandem Mass Spectrometry

• Agilent 1290 Infinity II LC system coupled to an Agilent 6490 triple quadrupole MS with Jet Stream electrospray ion source.
• ZORBAX Eclipse Plus C18 column (2.1×100 mm, 1.8 µm) at 40 °C, ACN–water gradient with ammonium formate and ammonium fluoride modifiers.

Gas Chromatography–Tandem Mass Spectrometry

• Agilent 8890 GC with 7000E triple quadrupole MS, multimode inlet and midcolumn backflush using two HP-5ms columns.
• Cold splitless injection, helium carrier gas and dynamic MRM acquisition aligned to the Agilent Pesticide & Environmental Pollutant database.

Main Results and Discussion

Matrix Removal and Cleanup

• Dry-residue measurements indicated approximately 60% of co-extractives were removed by EMR–GPD, outperforming conventional dispersive SPE by 4–10% in background reduction.
• Early-eluting polar interferences were effectively eliminated, and pigment removal improved signal-to-noise for LC and GC analyses.

Recovery, Precision and Matrix Effect

• Over 95% of target pesticides achieved average recoveries between 70% and 120% at 10 ng/g spiking levels; more than 97% showed relative standard deviations below 20%.
• Matrix effects on LC/MS/MS fell within ±40% for over 85% of compounds, demonstrating acceptable ion suppression or enhancement.

Calibration Performance

• Full dynamic range (5–5 000 ng/g) with R²>0.99 was attained for 88% of pesticides using linear regression and for 5% using quadratic fits.
• Approximately 6% of analytes required a modified calibration range due to limited low-end sensitivity or interferences.

Benefits and Practical Applications of the Method

• The passthrough cleanup with Captiva EMR–GPD simplifies workflows, reducing hands-on time compared to multi-step dispersive SPE protocols.
• High throughput capability supports routine monitoring of extensive pesticide panels in compliance with regulatory standards.
• Robust cleanup and calibration strategies ensure reliable results in complex spice matrices such as cinnamon.

Future Trends and Potential Applications

• Extending the EMR-GPD cleanup approach to other pigmented or fatty food matrices, including herbs, teas and essential oils.
• Integration with high-resolution mass spectrometry to expand target lists and identify non-target contaminants.
• Automation of sample preparation using positive-pressure manifolds and robotics to further increase laboratory throughput.
• Application of machine learning for predictive optimization of cleanup conditions based on matrix composition.

Conclusion

The combined QuEChERS AOAC extraction and Captiva EMR–GPD passthrough cleanup method, coupled with LC/MS/MS and GC/MS/MS detection, provides a rapid, reliable and sensitive platform for the simultaneous determination of over 300 pesticide residues in cinnamon powder. The approach delivers efficient matrix removal, strong quantitation performance and streamlined laboratory workflows, supporting regulatory compliance and food safety assurance.

References

1. European Commission. EU Pesticides Database. http://ec.europa.eu/food/plant/pesticides/eu-pesticides-database/ public
2. SANTE/11312/2021: Analytical quality control and method validation procedures for pesticide residues analysis in food and feed.
3. Lacina O.; Adam V.; Klejdus B.; Havlicek L. Critical Assessment of Extraction Methods for the Simultaneous Determination of Pesticides Residues and Mycotoxins in Fruits, Cereals, Spices and Oil Seeds Employing Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry. J. Chromatogr. A 2021, 1262(4), 8–18.
4. Zhang Z.; Wang N.; Cao J.; et al. Evaluation of Cleanup Procedures in Pesticides Multi-Residue Analysis with QuEChERS in Cinnamon Bark. Food Chem. 2019, 276, 140–146.
5. Andrianova A.A.; Zhao L. Five Keys of Unlock Maximum Performance in the Analysis of Over 200 Pesticides in Challenging Food Matrices by GC/MS/MS. Agilent Technologies Application Note 5994-4965EN, 2022.
6. Zhao L.; Wei T. Determination of Multiclass, Multiresidue Pesticides in Spring Leaf Mix Using Captiva EMR-HCF Passthrough Cleanup and LC/MS/MS. Agilent Technologies Application Note 5994-4765EN, 2022.
7. Zhao L.; Andrianova A.A. Determination of Over 300 Pesticides in Cayenne Pepper Using Captiva EMR–GPD Passthrough Cleanup and LC/MS/MS and GC/MS/MS. Agilent Technologies Application Note 5994-5630EN, 2023.