Rapid Profiling and Authentication of Cinnamon Samples Using Ambient Ionization (DART) and Single Quadrupole Mass Spectrometry

Importance of the Topic

Cinnamon is a widely used spice and herbal medicine derived from the inner bark of Cinnamomum species. It is vulnerable to economic adulteration, especially substituting true Ceylon cinnamon with cheaper varieties that contain high levels of coumarin. Coumarin poses potential hepatotoxic risks, making species authentication critical for food safety and quality assurance.

Objectives and Study Overview

This study aims to demonstrate a rapid and user-friendly approach for identifying Cinnamomum species in ground and whole cinnamon samples. By coupling Direct Analysis in Real Time ambient ionization with a single quadrupole mass detector, the method seeks to eliminate extensive sample preparation and chromatographic separation while providing reliable species differentiation.

Used Instrumentation

• DART ion source operating at 450 °C with helium gas, grid voltage 350 V, sampling speed 1.0 mm/sec
• ACQUITY QDa single quadrupole mass detector with cone voltage 5 V, mass range 50–500 amu, acquisition rate 2 Hz
• MassLynx MS software for data acquisition and analysis

Methodology

A total of 15 cinnamon samples were analyzed, including 12 ground samples and 3 whole sticks. Ground samples were applied to a 12-position QuickStrip card by swabbing, while sticks were held in the DART beam with tweezers. Each card scan required less than five minutes, and no chromatographic steps were needed, preserving instrument cleanliness and accelerating throughput.

Main Results and Discussion

For whole cinnamon sticks, species differentiation was based on the relative intensities of cinnamaldehyde at m/z 133 and coumarin at m/z 147. Cinnamomum verum showed a dominant cinnamaldehyde signal with minimal coumarin, whereas C. burmannii displayed a strong coumarin peak. In ground samples, distinct profiles emerged:

• C. verum exhibited strong cinnamaldehyde and methyl cinnamate signals and negligible coumarin
• C. cassia featured predominant cinnamaldehyde with minor coumarin and methyl cinnamate
• C. burmannii and C. loureiroi both showed dominant coumarin, with C. loureiroi also containing significant methyl cinnamate

One unknown sample displayed a mixed profile of Ceylon and coumarin-rich species, indicating possible adulteration or blending.

Benefits and Practical Applications

This ambient MS approach offers:

• Rapid screening of up to 12 samples in under five minutes
• Minimal or no sample preparation and no chromatography
• Direct and clear species differentiation based on characteristic ions
• Practical implementation for quality control, authenticity testing, and food safety monitoring

Future Trends and Potential Applications

Future developments may include:

• Extension to authentication of other spices and botanicals
• Integration of chemometric algorithms for automated classification
• Portable DART-MS platforms for on-site testing
• Higher throughput sampling modules and automated workflows
• Combining with high-resolution MS to enhance selectivity and sensitivity

Conclusion

The combination of DART ambient ionization with a single quadrupole MS detector provides a fast, user-friendly, and robust method for cinnamon species authentication. It effectively distinguishes true Ceylon cinnamon from cheaper, coumarin-rich varieties, supporting food quality and safety efforts.

Reference

• Wang YH Avula B Nanayakkara NPD Zhao J Khan IA Cassia Cinnamon as a Source of Coumarin in Cinnamon-Flavored Food and Food Supplements in the United States J Agric Food Chem 2013 61 4470–4476
• Cody RB Laramee JA Durst HD Versatile New Ion Source for the Analysis of Materials in Open Air Under Ambient Conditions Anal Chem 2005 77 2297–2302