Non-Targeted Screening of Lipophilic Marine Biotoxins by Liquid Chromatography – High-Resolution Mass Spectrometry

Significance of the topic

Marine lipophilic biotoxins produced by harmful algal blooms pose a critical food safety risk when accumulated in shellfish. Rapid, accurate screening methods are essential to protect public health and sustain commercial shellfish markets.

Objectives and overview of the study

This work demonstrates a non-targeted screening approach for eight classes of lipophilic marine toxins in shellfish tissue using liquid chromatography coupled to high-resolution Orbitrap mass spectrometry. The method was optimized with certified standards and applied to a mussel reference extract.

Methodology

Sample preparation involved homogenizing mussel tissue in 80% methanol, followed by sequential extraction steps, centrifugation and filtration. LC separation used a reversed-phase C18 column with a 10–90% acetonitrile gradient in 6 min. Full-scan MS data were acquired in alternating positive and negative ion modes at 50,000 resolution, 2 Hz scan rate, and 5 ppm mass window extraction.

Instrumentation

• Thermo Scientific Exactive™ benchtop LC–MS system with Orbitrap analyzer
• Thermo Scientific Accela™ HPLC and Hypersil GOLD C18 column (2.1×100 mm, 1.9 µm)
• HESI-II electrospray ion source
• Polytron PT3000 tissue homogenizer
• Standard mussel tissue reference material (CRM-DSP-Mus-b)

Results and Discussion

Eight toxin standards (okadaic acid, DTX1, DTX2, PTX2, AZA1-3, YTX) were baseline separated in under 6 min. Mass accuracy was <3 ppm in negative mode and <1 ppm in positive mode. Limits of detection ranged from 0.052 to 5.1 µg/L. Analysis of mussel extract yielded okadaic acid and DTX1 at 4.1 and 0.58 µg/g respectively, with ~10% RSD. Observed values were about half the certified levels due to matrix ion suppression, which can be addressed by matrix-matched calibration.

Benefits and practical applications

• Non-targeted full-scan approach detects known and unknown analogues without individual method tuning
• High mass accuracy and resolution ensure selectivity in complex matrices
• Rapid analysis (<6 min) supports high throughput monitoring
• Expandable target list by adding masses in data processing

Future trends and potential applications

Advances in orbitrap resolution and scan speed will enhance detection of trace biotoxins and emergent analogues. Integration with automated data processing and matrix-matched standards will improve quantification accuracy. The workflow can be extended to other food safety and environmental toxin screening applications.

Conclusion

The Exactive benchtop LC–Orbitrap MS system provides a robust, non-targeted screening method for lipophilic marine biotoxins in shellfish. High resolution, full-scan data enable rapid, selective detection and quantification, offering a versatile tool for routine food safety monitoring.

References

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