Combine Dispersive Pipette XTRaction and SALLE (Salt Assisted Liquid-Liquid Extraction) for a novel cleanup mechanism

Dispersive Pipette XTRaction + SALLE

XTR tips can house sorbents like weak anion exchange (WAX) or reverse phase (RP) for cleanup and the salt (S) necessary for SALLE. This methodology is ideal for applications that require acetonitrile for protein precipitation and are focused on hydrophobic analytes.

Aspirate and dispense steps mix sample solution with sorbent and salt. The salt dissolves in the solution and the acetonitrile separates due to the increased ionic strength of the solution. The upper acetonitrile layer is transferred to a clean vial. The solution from the upper layer can be analyzed directly or after dilution with water. Alternatively the solution can be solvent evaporated and reconstituted in LC mobile phase depending on the workflow for your application.

This methodology is another example of the unique customization available with XTR tips for INTip solid phase extraction. The amount of sorbent and salt in each tip can be scaled up or down depending on the sample volume.

WAX-S Methods:

WAX-S methods have been tested and validated by a number of forensic and clinical labs for a variety of applications. Extraction protocols using WAX-S XTR tips have been used for sample cleanup for biological samples like urine and blood or serum in various publications including: Journal of Analytical Toxicology, Journal of Analytical Chemistry and Journal of Chromatography A.

WAX-S XTR tips were featured by Stanford Health Care during a poster presentation as the Mass Spectrometry Applications to the Clinical Lab (MSACL) conference and expo in 2015 in a method for the analysis of Cortisol in Urine and Saliva. You can download an application note for this method in the link below. WAX-S methods provide fast extraction efficiency for removing matrix interferences. Review journal articles or applications notes using this method.

DPX + SALLE Extraction Video Using WAX-S XTR Tips

Learn more about XTR tips