Isotope dilution LC-MS/MS for the quantification of ergot alkaloids: a comparative study

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Mycotoxicology

Background:

• Ergot alkaloids (EAs) are toxic fungal metabolites found in cereal crops.
• The European Commission set maximum levels for 12 priority EAs in foodstuffs in 2022.
• Accurate monitoring of EAs is crucial for food safety but challenged by a lack of internal standards.

Purpose of the Study:

• To evaluate the performance of newly synthesized isotope-labeled internal standards (ISTDs) for 12 priority EAs.
• To develop and validate a reference material (RM) for EAs in rye flour.
• To improve the reliability of EA analysis in cereals and related products.

Main Methods:

• Synthesis of isotope-labeled internal standards (ISTDs) for 12 priority EAs.
• Interlaboratory comparison of ISTDs against the standard addition method (EN 17425).
• Development of an EA reference material in rye flour using stable isotope dilution mass spectrometry (SIDMS) as the primary method, following ISO 33405 guidelines.

Main Results:

• The developed ISTDs significantly enhanced method precision and trueness for EA quantification.
• Results obtained using ISTDs showed good agreement between participating laboratories.
• A certified reference material for EAs in rye flour was successfully produced, supporting analytical method validation.

Conclusions:

• Isotope-labeled internal standards are effective tools for improving the accuracy and reliability of ergot alkaloid monitoring in cereals.
• The developed reference material provides a crucial benchmark for EA analysis, contributing to safer food supplies.
• These advancements support regulatory compliance and enhance consumer protection against EA contamination.