Determination of MCPD and glycidyl esters in foodstuff

Significance of the Topic

The analysis of 3-MCPD, 2-MCPD and glycidyl esters in refined fats and oils is critical due to their formation under high-temperature refining and potential carcinogenicity. Regulatory bodies such as EFSA have set strict tolerable daily intake limits, driving demand for reliable, high-throughput analytical methods in food quality control and safety laboratories.

Objectives and Overview of the Study

This work presents the development and validation of an automated sample-preparation workflow called “DGF Fast and Clean” for the indirect determination of MCPD and glycidyl esters. Using the CHRONECT Workstation MCPD, the goal was to integrate transesterification, quenching, extraction, derivatization, clean-up and GC-MS/MS analysis to reduce hands-on time, improve reproducibility and maintain compliance with established DGF/AOCS methods.

Methodology and Instrumentation

Automation was performed on a CTC PAL3 DHR autosampler coupled to a Bruker EVOQ GC-TQ (456-GC) under CHRONOS control. Key steps include:

• Transesterification in two parts (A and B) to release bound MCPD and glycidol under chloride or chloride-free conditions.
• Quenching with NaCl or NaBr solutions.
• Liquid-liquid extraction of free MCPD.
• Derivatization using phenylboronic acid.
• Clean-Technology clean-up module to protect the GC-MS ion source and extend maintenance intervals.
• MRM detection of analytes and deuterated internal standards on the triple quadrupole.

Key Results and Discussion

Validation against the classical DGF method showed recoveries of 91–116 % and reproducibility RSDs of 7–9 % for the new workflow, comparable to manual protocols. Limits of detection were 0.026 mg/kg for 3-MCPD with quantification at 0.041 mg/kg. Sample throughput increased dramatically: one complete analysis in 45 min versus up to 18 h manually. Automated results agreed closely with reference oils (FAPAS) and manual DGF and SGS 3-in-1 methods, demonstrating robustness and accuracy.

Benefits and Practical Applications

The integrated CHRONECT Workstation MCPD delivers high-throughput, consistent data while minimizing manual intervention. Backflush protection prolongs instrument uptime. The system is ideal for routine QA/QC laboratories, service providers and industrial analytics of fats and oils requiring regulatory compliance.

Future Trends and Potential Uses

Modularity of the PAL3 platform allows adaptation to other sample-preparation workflows (Unilever, Zwagerman-Overman, Weisshaar methods). Potential developments include online process monitoring, expanded analyte panels, further miniaturization and integration with high-resolution MS for lipid-bound contaminants.

Conclusion

The automated “DGF Fast and Clean” workflow on the CHRONECT Workstation MCPD offers a rapid, reliable and reproducible solution for MCPD and glycidyl ester analysis in foodstuffs, meeting modern regulatory requirements and laboratory productivity needs.

Reference

• AS Application Note 1603, CHRONECT Workstation MCPD, Axel Semrau GmbH & Co. KG, March 2018