ACQUITY UPLC I-Class/Xevo TQD IVD System: Analytical Performance for Antibiotics

Significance of the Topic

The reliable quantification of antibiotics in human plasma is essential for therapeutic drug monitoring, pharmacokinetic studies and clinical research. High throughput and robust analytical methods help laboratories maintain precision, sensitivity and reproducibility when measuring a wide panel of antimicrobial agents.

Goals and Study Overview

This application note evaluates the analytical performance of the Waters ACQUITY UPLC I-Class/Xevo TQD IVD System for simultaneous quantification of 16 antibiotics and beta-lactam inhibitors (e.g., ampicillin, azithromycin, cefepime, meropenem, piperacillin/sulbactam) in plasma. The primary objectives were to demonstrate selectivity, sensitivity, calibration linearity and precision over clinically relevant concentration ranges.

Methodology

Sample preparation and chromatographic-mass spectrometric conditions were optimized as follows:

• Sample Prep: 50 µL plasma precipitated with methanol, centrifuged, diluted in acidified water
• LC Column: ACQUITY UPLC BEH C18, 1.7 µm, 2.1×100 mm
• Mobile Phase A: 0.1% ammonia in water; B: methanol; Flow: 0.5 mL/min
• Gradient: 90% A to 0% A over 3 min, hold then re-equilibrate by 5 min
• MS: Xevo TQD IVD, MRM acquisition, ESI positive/negative, MS1/MS2 resolution 0.75 FWHM
• Software: MassLynx v4.2 control, TargetLynx XS data processing

Used Instrumentation

• Waters ACQUITY UPLC I-Class/Xevo TQD IVD System
• MassLynx MS Software v4.2
• TargetLynx XS Application Manager

Results and Discussion

Chromatographic profiles showed excellent separation of all compounds within a 5 min run. Calibration models achieved r²>0.995 (linear for select β-lactams, quadratic for others). Lower limits of quantification (LLOQ) met S/N>10 and ≤20% RSD criteria. Inter- and intra-day precision for quality controls fell below 15% RSD across 5 days (n=25).

Contributions and Practical Applications

• Demonstrates rapid, high-throughput antibiotic quantification in clinical research or QA/QC labs
• Supports accurate monitoring of antibiotic levels for dose optimization

Future Trends and Potential Applications

• Extension to additional antibiotic classes and metabolites
• Integration with laboratory automation for fully walk-away workflows
• Application to other biological matrices (urine, CSF)
• Coupling with high-resolution MS for structural elucidation of degradation products

Conclusion

The Waters ACQUITY UPLC I-Class/Xevo TQD IVD System delivers rapid, selective and precise quantification of a broad antibiotic panel in plasma. Its robust performance and software integration make it well suited for clinical research and routine QA/QC environments.