An enhanced LC-MRM-MS platform for sensitive and simultaneous quantification of cyclic imines in shellfish

Area of Science:

• Marine Biology
• Analytical Chemistry
• Environmental Science

Background:

• Cyclic imines (CIs) are novel marine biotoxins produced by microalgae, accumulating in marine food chains.
• Their prevalence is increasing due to marine ecosystem changes, posing toxicological risks.
• Analytical monitoring of CIs is challenging due to numerous analogues and interfering substances.

Purpose of the Study:

• To develop a sensitive and selective analytical platform for the simultaneous quantitation of marine-derived CIs.
• To establish a method for monitoring CIs in shellfish species.

Main Methods:

• Development of a liquid chromatography/multiple reaction monitoring-mass spectrometry (LC/MRM-MS) quantitative platform.
• Utilized chromatographic separation based on CI hydrophobicity and MS/MS for structure-specific ion monitoring.
• Enriched for marine-derived CIs for enhanced selectivity and sensitivity.

Main Results:

• Successfully monitored seven CIs simultaneously, including pinnatoxins, gymnodimine, and spirolides.
• Achieved part-per-trillion (ppt) level quantitation for PnTX G, GYM A, and 13-desMe SPX C in shellfish.
• Determined that seasonal factors, rather than species, more significantly influenced CI expression in Korean Peninsula shellfish.

Conclusions:

• The developed LC/MRM-MS platform offers high sensitivity and selectivity for simultaneous CI quantitation.
• This method is applicable to marine biology and other fields requiring CI analysis.
• Seasonal variations are a key factor in CI occurrence in the studied region.