Oasis PRiME HLB Cartridge for Cleanup of Infant Formula Extracts Prior to UPLC-MS/MS Multiresidue Veterinary Drugs Analysis

Significance of the Topic

The analysis of veterinary drug residues in infant formula is critical to ensure food safety and public health. Infant formula is a complex matrix containing proteins, fats, and phospholipids that can interfere with LC-MS/MS measurements and damage instrumentation. A robust sample cleanup method that efficiently removes these interferences while maintaining high recovery of a broad range of veterinary drugs is essential.

Objectives and Overview

This study aims to develop a streamlined, multiclass sample preparation and UPLC-MS/MS method to quantify veterinary drug residues in powdered infant formula. Representative compounds from tetracyclines, fluoroquinolones, sulfonamides, macrolides, beta-lactams, NSAIDs, steroids, and beta-agonists were spiked into formula samples to evaluate method performance.

Methodology

• Initial Extraction and Protein Precipitation: 0.5 g of formula was extracted with acidified acetonitrile/water, vortexed, shaken, and centrifuged to remove proteins.
• SPE Cleanup with Oasis PRiME HLB: A 3 cc, 60 mg cartridge was used in pass-through mode without conditioning. 0.5 mL of supernatant was applied, and the cleaned extract was collected and diluted before analysis.
• UPLC-MS/MS Analysis: Separation on an ACQUITY UPLC CSH C18 column (1.7 µm, 100 mm × 2.1 mm) using a gradient of aqueous 0.1% formic acid and acetonitrile with 0.1% formic acid. Detection on a Xevo TQ-S triple quadrupole mass spectrometer in positive electrospray ionization mode with optimized MRM transitions.

Instrumentation

• UPLC: ACQUITY UPLC I-Class system
• Column: ACQUITY UPLC CSH C18, 1.7 µm, 100 mm × 2.1 mm
• Mass Spectrometer: Xevo TQ-S with electrospray ionization
• Software: MassLynx v4.1

Main Results and Discussion

• Phospholipid Removal: The Oasis PRiME HLB cartridge removed over 95% of phospholipids, protecting the column and MS source.
• Recovery: Most compounds showed overall method recoveries above 70%, with matrix effects averaging around 40% for infant formula.
• Reproducibility: Recoveries at low and high spike levels ranged between 29% and 130%, with relative standard deviations (RSD) generally below 15%.
• Sensitivity and Linearity: Calibration curves exhibited linearity (R2 > 0.99) over relevant concentration ranges for all analytes.

Benefits and Practical Applications

• Efficiency: One-step pass-through cleanup eliminates conditioning steps and reduces hands-on time.
• Versatility: Applicable to a wide range of veterinary drugs with diverse polarity.
• Instrument Protection: Effective removal of fats and phospholipids extends column and MS maintenance intervals.
• Simplicity: No additional filtration required before UPLC-MS/MS analysis.

Future Trends and Applications

Rapid SPE technologies like Oasis PRiME HLB will continue to evolve, addressing more complex food matrices. Advances in high-throughput UPLC-MS/MS platforms and automated sample preparation will further streamline residue analysis. Integration with multiclass, multi-residue workflows can expand to other infant foods and nutraceutical products, enhancing routine monitoring capabilities.

Conclusion

A simple extraction and one-step Oasis PRiME HLB cleanup enables reliable, high-throughput UPLC-MS/MS analysis of veterinary drug residues in infant formula. The method delivers high recoveries, effective removal of matrix interferences, and robust performance across multiple drug classes, supporting regulatory compliance and consumer safety.

References

• M. Young and K. Tran. Oasis PRiME HLB Cartridge for Effective Cleanup of Meat Extracts Prior to Multi-Residue Veterinary Drug UPLC-MS Analysis. Waters Technology Brief 720005411EN, 2015.
• M. Young and K. Tran. Rapid, Simple, and Effective Cleanup of Seafood Extracts Prior to UPLC-MS/MS Multiresidue Veterinary Drugs Analysis. Waters Application Note 720005488EN, 2015.