Determination of nitrofuran metabolite residues in shrimp by LC-MS/MS

Significance of the Topic

Residues of nitrofuran metabolites in aquatic products pose a risk to food safety and public health. Shrimp is a commonly consumed seafood, and monitoring trace levels of banned veterinary drugs is essential to ensure compliance with regulatory standards and protect consumer health.

Objectives and Study Overview

This study presents the development and validation of a rapid, sensitive LC-MS/MS method for quantifying four nitrofuran metabolite derivatives (AOZ, AMOZ, AHD, SEM) in shrimp. The method integrates acid hydrolysis, derivatization, and triple quadrupole mass spectrometric detection.

Methodology and Instrumentation

• Sample preparation: Acid hydrolysis in HCl with 2-nitrobenzaldehyde, derivatization at 37 °C for 16 h, neutralization, ethyl acetate extraction, nitrogen drying, reconstitution and filtration.
• Chromatography: UHPLC on Shim-pack GISS C18 (100 mm × 2.1 mm, 1.9 μm); mobile phase A = 0.002 M ammonium acetate, B = methanol; gradient elution (10%–95% B) at 0.35 mL/min, 35 °C, injection 10 μL; run time 8 min including column wash.
• Mass spectrometry: Shimadzu LCMS-8045 triple quadrupole with ESI in positive MRM mode; rapid polarity switching and up to 555 transitions per second; optimized ion source parameters using LabSolutions MRM Connect.

Results and Discussion

• Separation: Baseline resolution of four derivatives achieved within 8 min.
• Linearity: Concentration range 0.5–20 μg/L with correlation coefficients (r) > 0.999.
• Sensitivity: Limits of detection between 0.06–0.11 ng/mL.
• Precision: Instrumental repeatability showed RSD of retention time 0.08–0.13% and peak area RSD 0.89–9.28%.
• Recovery: Spiked shrimp at 1, 5, 10 μg/kg yielded recoveries of 82.3–112.7% (n = 3).
• Real samples: No nitrofuran metabolites detected in three supermarket shrimp samples.

Benefits and Practical Applications

The method offers a rapid (8 min per sample), robust and highly sensitive approach for routine monitoring of nitrofuran residues in seafood. Its high throughput and reliable quantification support food safety laboratories in regulatory compliance and quality control.

Future Trends and Applications

• Automation of sample preparation to increase throughput.
• Extension to other aquatic species and complex food matrices.
• Integration with high-resolution mass spectrometry for non-target screening of emerging contaminants.
• Development of portable LC-MS/MS platforms for on-site testing.

Conclusion

A validated LC-MS/MS protocol enables accurate detection of nitrofuran metabolites in shrimp at parts-per-billion levels. The method’s excellent linearity, precision and recovery demonstrate its suitability for routine food safety monitoring.

Reference

Dan Luo, Qiang Li, Hongyuan Hao, Taohong Huang. Determination of nitrofuran metabolite residues in shrimp by LC-MS/MS (Application Note MP 209, Shimadzu (China) Co., Ltd.).