Determination of the Derivatives of Nitrofuran Metabolites in Marine Products by Ultra High Performance Liquid Chromatography / Triple Quadrupole Mass Spectrometry

Significance of the Topic

Nitrofuran metabolites used in aquaculture pose health risks due to carcinogenic effects.
Monitoring their residues in seafood aligns with regulatory limits set by agencies such as the US FDA.
Sensitive and reliable analytical methods ensure food safety and support quality control in the seafood industry.

Objectives and Study Overview

This study aims to develop a rapid and robust ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-MS/MS) method for the quantitative determination of four nitrofuran derivative metabolites (AOZ, AMOZ, AHD, SEM) in marine products.
The method targets compliance with the US FDA guideline limit of 0.5 µg/kg for AMOZ and equivalent thresholds for other analytes.

Methodology and Instrumentation

The analytical workflow comprises derivatization, extraction, and UHPLC-MS/MS analysis.

1. Derivatization with o-nitrobenzaldehyde at 37 °C for 16 h.
2. Liquid–liquid extraction using ethyl acetate, followed by solvent evaporation and reconstitution in 0.1% aqueous formic acid.
3. Defatting step with n-hexane and filtration through a microporous membrane.

Instrumentation details:

• UHPLC system: Shimadzu Nexera with Shim-pack XR-ODS III column (150 mm × 2.0 mm i.d., 2.2 µm) at 40 °C.
• Mobile phase: 0.02% formic acid in water (A) and acetonitrile (B); gradient 40% B to 95% B over 1.5 min, return to 40% B by 4.0 min; flow rate 0.4 mL/min.
• Mass spectrometer: Shimadzu LCMS-8030 triple quadrupole with ESI in positive mode; MRM transitions optimized for each analyte.

Main Results and Discussion

The UHPLC-MS/MS method achieved baseline separation of all analytes within 4 minutes.
Calibration curves were linear from 1 to 200 µg/L with correlation coefficients exceeding 0.999.
Limits of quantitation reached 0.4 µg/kg for AMOZ, meeting regulatory requirements.
Repeatability tests (n = 6) showed relative standard deviations below 4.8% for peak areas and below 0.3% for retention times across multiple concentration levels.

Benefits and Practical Applications

• High-throughput screening of seafood for nitrofuran residues.
• Enhanced sensitivity supports detection below regulatory thresholds.
• Short analysis time promotes efficient routine monitoring and quality control.

Future Trends and Applications

Advances may include expansion to additional food matrices and broader residue panels.
Integration with automated sample preparation can improve laboratory efficiency.
High-resolution mass spectrometry and data analytics could further enhance specificity and quantitation.

Conclusion

A sensitive and rapid UHPLC-MS/MS method was established for four nitrofuran derivative metabolites in marine products.
The protocol offers robust quantitation, regulatory compliance, and suitability for routine food safety testing.

References

No formal literature references were provided in the original document.