Quantitative analysis of sulfonamides in meat muscle matrix with a field asymmetric ion mobility interface on an Orbitrap Mass spectrometer

Importance of the Topic

Reliable detection of sulfonamide residues in meat matrices is essential for food safety and regulatory compliance. Traditional LC-MS analyses can suffer from matrix-induced signal suppression and frequent instrument maintenance due to high loads of coextracted compounds.

Objectives and Study Overview

This study assesses the benefits of coupling a Field Asymmetric Ion Mobility Spectrometry (FAIMS) interface to an Orbitrap Exploris 240 MS for quantitative analysis of sulfonamides in meat muscle extract. It compares limits of quantification, matrix reduction, and long-term instrument performance with and without FAIMS.

Methodology and Instrumentation

• Sample Preparation: Meat muscle was extracted via a modified QuEChERS protocol using ammonium oxalate/EDTA buffer, acetonitrile, CEC18 cleanup, and dilution in 0.1% formic acid.
• LC-MS Method: Separation employed a Polar Advantage II UHPLC column with a gradient of 0.1% formic acid in water (solvent A) and methanol (solvent B). Five compensation voltages (CVs) were optimized per analyte in a looped scan sequence.
• Data Analysis: Limits of quantification (LOQs) were defined by <20% RSD and <20% bias using TraceFinder software. Matrix compound reduction was evaluated with Compound Discoverer in an advanced data-dependent acquisition mode.

Instrumentation

• Thermo Scientific Exploris 240 Orbitrap mass spectrometer
• Thermo Scientific FAIMS Pro Duo interface
• Thermo Scientific Vanquish Horizon UHPLC system

Results and Discussion

• LOQ Improvements: FAIMS maintained or improved LOQs for multiple sulfonamides, enabling reliable quantification down to sub-µg/L levels.
• Matrix Reduction: FAIMS reduced the number of compounds entering the MS from 6055 to 2804, mitigating matrix suppression.
• Selective Transmission: Distinct CV optima for matrix ions versus target analytes allowed targeted ion filtering and enhanced signal-to-noise ratios.
• Instrument Robustness: Over 84 hours of continuous operation, signal intensity remained stable across all CV settings, demonstrating improved uptime.

Benefits and Practical Applications

• Enhanced Sensitivity: Lower LOQs facilitate compliance with stringent regulatory thresholds.
• Reduced Maintenance: Lower matrix load decreases cleaning frequency and downtime.
• Adaptable Workflow: The FAIMS-LC-MS/MS approach can be extended to other small-molecule analyses in complex food or biological matrices.

Future Trends and Potential Applications

Ongoing advancements in FAIMS technology and software promise real-time matrix suppression and automated CV optimization. Integration with high-resolution mass spectrometry will expand targeted and non-targeted screening of veterinary drugs and contaminants.

Conclusion

Integrating FAIMS with Orbitrap-based LC-MS/MS enhances sensitivity and robustness for sulfonamide quantification in meat muscle matrices. This orthogonal separation strategy effectively reduces matrix interference, lowers LOQs, and supports high-throughput food safety monitoring.