Classification of N-Nitrosamines and Other Nitroso Compounds by Using Tandem Mass Spectrometry Experiments Based on...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Organic Chemistry

Background:

• Nitroso compounds are a significant class of chemicals with diverse applications and toxicological relevance.
• Accurate detection and classification of nitroso compounds are crucial for environmental monitoring, food safety, and biomedical research.
• Existing methods for nitroso compound detection may lack general applicability or specificity.

Purpose of the Study:

• To develop a general method for the detection and classification of nitroso compounds using mass spectrometry (MSn) experiments.
• To identify diagnostic fragmentation reactions specific to nitroso compounds under collision-activated dissociation (CAD).
• To create a decision tree for classifying unknown nitroso compounds based on observed fragmentation patterns.

Main Methods:

• Utilized MSn (n=2 or 3) experiments with collision-activated dissociation (CAD) to analyze fragmentation reactions.
• Examined fragmentation patterns of 36 protonated nitroso model compounds and 46 published examples.
• Identified four key diagnostic fragmentation reactions indicative of nitroso compounds.

Main Results:

• Over 80% (69/82) of model nitroso compounds were successfully classified using the developed MSn-CAD method.
• The method effectively classified most N-nitrosamines, but specific classification of N-nitrosamines was limited.
• C-nitroso compounds presented a greater challenge, with only 57% undergoing diagnostic fragmentation.

Conclusions:

• The developed MSn-CAD method provides a robust approach for the general detection and classification of nitroso compounds.
• A decision tree based on diagnostic fragmentation reactions aids in the structural characterization of unknown nitroso compounds.
• Further refinement may be needed for specific classification of C-nitroso compounds and certain N-nitrosamines.