• Application Note

Oasis Sample Extraction Products: Enhanced Sensitivity Using µElution Plate

Oasis Sample Extraction Products: Enhanced Sensitivity Using µElution Plate

  • Waters Corporation

This is an Application Brief and does not contain a detailed Experimental section.


This application brief describes about Oasis μElution plates in combination with Oasis sorbents that are an ideal solution for small sample volumes up to 375 mL, providing up to a 15X increase in concentration.


Waters Oasis μElution plates combine patented plate design and proven Oasis chemistries to provide high analyte recovery and clean extracts in elution volumes as low as 25 μL. This can enhance a bioanalytical assay’s sensitivity and allow scientists to easily achieve their required LLOQs.

  • Ideal for small sample volumes (10-25 μL)
  • Eliminates evaporation and reconstitution
  • Offers up to a 15X increase in concentration without evaporation
  • Excellent recovery for a diverse range of therapeutic peptides

Results and Discussion

Superior Sensitivity with μElution format

The Oasis μElution format offers sample enrichment of up to 15X, providing superior sensitivity to bioanalytical assays.

Risperidone response: 15X increase in concentration

375 μL of 0.5 ng/mL risperidone in human plasma sample extracted with Oasis MCX μElution plate a) MCX μElution and b) MCX 10 mg.

Highest SPE Recoveries

Oasis sorbents are water-wettable which allows them to maintain high retention and capacity for a variety of analytes even if the well or cartridge runs dry. With Oasis sorbents, the analytical scientist can be assured of reliable, robust performance and the highest degree of recovery possible.

The efficient therapeutic peptide solid-phase extraction (SPE) screening strategy, based on a single protocol and two of the Oasis mixed-mode sorbents in μElution format, simplifies method development for the extraction of peptides from human plasma and provide excellent recoveries for diverse set of peptides.

Excellent SPE Recovery for 12 Peptides

Excellent recovery for 12 diverse peptites using Oasis Mixed-Mode SPE in μElution plate format.

Lowest Matrix Effects

The combination of Oasis mixed-mode SPE and the μElution format provide the cleanest SPE extract possible, facilitating the meeting of regulatory bioanalytical requirements.

Matrix Effects for 1 ng/mL of Imipramine, Nonafluoropentanoic Acid, Ibuprofen, and Valethamate in Human Plasma

Matrix effect results of 4 diverse small molecules on 4 mixed-mode Oasis chemistries in (1 ng/mL in human plasma).

μElution Plate Loading Capacity

The physicochemical properties of Oasis sorbents are designed to provide exceptionally high loading capacity, even though each well in a Waters Oasis μElution plate contains only 2 mg of Oasis sorbent.

To determine the Oasis μElution plate capacity, increasing volumes of plasma and urine samples (from 50 μL to 350 μL in 50 μL increments) were spiked with 200 ng/mL Imipramine (non-polar base) and 200 ng/mL Atenolol (polar base). The plasma aliquots were diluted 1:1 with 4% aqueous H3PO4 and the urine aliquots were diluted 1:1 with H2O and then loaded onto the μElution plate. SPE recovery was calculated and plotted for each loading level.

SPE Recovery for 200 ng/mL Imipramine and 200 ng/mL Atenolol on Oasis MCX μElution Plate


Using a unique plate design in combination with Oasis sorbents, the Oasis μElution plates are an ideal solution for small sample volumes up to 375 mL, providing up to a 15X increase in concentration. This concentration, along with excellent recoveries, equates to unparalled sensitivity for bioanalytical samples.

720003680, September 2010

Back To Top Back To Top