Waters Oasis sample preparation - Application Notebook

Significance of Oasis SPE Technologies

Solid-phase extraction (SPE) remains a cornerstone of analytical sample preparation, offering sensitive, selective, and reproducible cleanup prior to chromatographic analysis. The Waters Oasis family addresses critical challenges such as low recoveries, matrix interferences, and pH limitations across diverse matrices including environmental water, biological fluids, and food extracts.

Scope and Article Overview

This application notebook chronicles the development and performance of Oasis SPE sorbents—polymeric, water-wettable materials protected by multiple U.S. patents—and outlines a broad library of application examples covering acidic, basic, and neutral analytes in various matrices. Key milestones include the introduction of Oasis HLB (1996), mixed-mode ion exchangers MCX/WAX (1999), and μElution plates (2010), alongside workflow strategies such as the Oasis 2×4 Method and online SPE integrations.

Methodology and Instrumentation

• SPE sorbents: Oasis HLB, MCX, MAX, WCX, WAX, μElution
• Device formats: cartridges (1–6 cc), 96-well plates, μElution plates, online columns
• Chromatographic systems: Waters Alliance HPLC/UHPLC, ACQUITY UPLC
• Detection: LC–UV, LC–MS (ESI ±), LC–MS/MS (MRM), GC–MS, fluorescence, PDA
• Key modules: Alliance 2695/2795, ACQUITY, Quattro Ultima/Premier/ZQ, ZMD

Main Results and Discussion

Across hundreds of application notes, Oasis SPE demonstrates high recoveries (often >80–90 %), low relative standard deviations (<5–15 %), and effective matrix removal in challenging samples such as river water, wine, urine, plasma, food extracts, and environmental soils. Mixed-mode sorbents selectively fractionate acidic, basic, and neutral compounds, while μElution formats and online SPE reduce solvent usage and automate workflow for high-throughput analysis.

Practical Benefits and Applications

• Broad analyte scope: pesticides, pharmaceuticals, veterinary drugs, endocrine disruptors, alkaloids, peptides, DNA oligonucleotides
• Matrix versatility: environmental waters, beverages, biological fluids, food, soil, cell culture lysates
• Workflow advantages: simplified method development (2×4 Method), high analyte retention across pH range, minimal breakthrough, efficient elution

Future Trends and Opportunities

Emerging developments include microelution formats for reduced solvent and sample volumes, two-dimensional SPE–LC online hyphenations for increased selectivity, tailored sorbent chemistries for polar compounds, and integration with UHPLC–MS/MS and high-resolution mass spectrometry for sensitive biomarker and residue analysis. Automation and customization of SPE plates and cartridges will drive higher throughput in pharmaceutical, environmental, and clinical laboratories.

Conclusion

The Waters Oasis family provides a proven, flexible platform for robust SPE across a wide analytical landscape. Continuous innovation in sorbent design, device formats, and method strategies ensures reproducible cleanup, high sensitivity, and streamlined workflows in research and quality control laboratories.

Reference

Waters Corporation. Oasis Family of Sample Extraction Products Application Notebook, 2008.