Analysis of Sulfonamide Drugs in Water Using Agilent Bond Elut HLB Cartridges and LC/MS/MS

Significance of the topic

The release of sulfonamide antibiotics into water bodies poses risks to ecosystems and human health. Monitoring these compounds at trace levels is critical for environmental assessment and regulatory compliance.

Objectives and Study Overview

This work aims to develop and validate a quantitative method for 19 sulfonamide drugs and metabolites in water using Agilent Bond Elut HLB solid phase extraction followed by LC/MS/MS detection. The study covers method optimization, performance evaluation, and application to real samples.

Methodology and Instrumentation

• Sample preparation: 500 mL water samples adjusted to pH 4–7 with diluted HCl, spiked with isotopically labeled internal standards, and extracted by SPE using Bond Elut HLB cartridges (6 mL, 500 mg).
• SPE protocol: cartridges conditioned with methanol and water, sample loaded under vacuum at ~5 mL/min, washed with water, and eluted with methanol (2×4 mL). Extracts were dried under nitrogen at 40 °C, reconstituted in 1 mL of 1:1 methanol:water, and filtered (0.2 µm).
• Instrumentation: Agilent 1290 Infinity II UHPLC system with Poroshell 120 EC-C18 column (100×2.1 mm, 2.7 µm), gradient elution at 0.3 mL/min; Agilent 6470A triple quadrupole MS with Jet Stream electrospray ionization, operated in MRM mode with optimized gas temperatures, flows, and voltages.

Main Results and Discussion

The method exhibited strong linearity (R² > 0.995) over a concentration range of 2–200 ng/mL. Limits of detection were between 0.3 and 1.9 ng/L, and limits of quantitation ranged from 1.2 to 7.6 ng/L. In spiked control water, recoveries were 74–118% (RSD ≤ 13.2%), with slightly lower recoveries for sulfisoxazole at low spike levels. Analysis of ground surface water spiked at 100 ng/L yielded recoveries of 73.4–102% with RSDs below 8.8%, confirming method robustness in real matrices.

Benefits and Practical Applications of the Method

This validated SPE–LC/MS/MS workflow delivers sensitive, accurate, and reproducible quantitation of a broad panel of sulfonamide antibiotics in environmental water samples. It supports regulatory monitoring, contaminant fate studies, and water quality management.

Future Trends and Potential Applications

The approach can be extended to other pharmaceutical classes and emerging contaminants by adapting sorbent chemistries and MS acquisition strategies. Integration with automated sample preparation platforms and high-resolution mass spectrometry may further enhance throughput and analytical scope.

Conclusion

The developed method provides a reliable and flexible solution for trace-level analysis of 19 sulfonamide drugs in water, achieving excellent sensitivity, precision, and recovery. Its performance meets stringent environmental monitoring requirements and offers broad applicability for analytical laboratories.