This is an Application Brief and does not contain a detailed Experimental section.
Liquid chromatography mass spectrometry (LC-MS) analysis of complex biological samples often requires extensive sample cleanup to remove the undesirable components from the sample matrix, which otherwise will inadvertently affect the analysis, often resulting in MS ion signal suppression or enhancement. Mixed-mode solid-phase extraction (SPE) is a commonly used sample preparation technique for LC-MS analysis. However, developing mixed-mode SPE methods can be a challenging task. Not knowing where to start or which sorbents to choose can be daunting. Further adding to the complexity, most SPE workflows involve several steps for pipetting and transferring samples, reagents, and solvents. Automation of these pipetting and transfer workflows using expensive liquid handlers often involve complex programming and require expertly trained and dedicated personnel to perform the task. Performing workflows manually can be extremely tedious and prone to errors and requires good analytical skills to produce reproducible results. An automated SPE workflow for a quick, reliable, and reproducible mixed-mode SPE sorbent selection method development, using an Andrew+ Pipetting Robot connected and operated using OneLab, an easy-to-use browser-based software, is described in this application brief. The ease of Andrew+ automated mixed-mode SPE sorbent selection is demonstrated by extracting five analytes from spiked human blood plasma using Waters Oasis 96-Well µElution Plate.
Quantitative analysis of complex biological samples using LC-MS requires extensive sample cleanup to remove undesirable matrix components that may otherwise coelute and adversely affect the quantitation of the target analyte. Mixed-mode SPE, where the sorbent exhibits both reversed-phase and ion-exchange properties, is an effective and well proven technique for sample cleanup. However, developing mixed-mode SPE methods for the quantitation of analytes can be a tedious process. It requires expert understanding of the physical and chemical properties of both the target analyte and the SPE sorbent, in order to select the most suitable sorbent for effective removal of undesired matrix components while affording highest analyte recovery.
Waters Oasis 96-Well μElution Plate (p/n: 186004475) simplifies this sorbent selection process, wherein it includes all four different mixed-mode ion-exchange sorbent chemistries (MCX, MAX, WAX, and WCX) in a single plate format and utilizes just two optimized and proven protocols (2x4 Sorbent Selection Method) (p/n: WA60090) to develop a good SPE method. Thus, the Oasis Method Development Plate, combined with these protocols, provides a streamlined and simplified solution to mixed-mode SPE sorbent selection, that will undoubtedly result in high analyte recovery. Furthermore, automation of this Oasis 2x4 Sorbent Selection Protocol by using the Andrew+ Pipetting Robot, controlled and programmed by the user-friendly, browser based OneLab Software, makes the entire sorbent selection method development rapid, accurate, reproducible, and robust.
In this application brief, a rapid, accurate, reproducible, and robust mixed-mode SPE sorbent selection method development is demonstrated using human blood plasma spiked with four analytes (imipramine, 1-decanesulfonic acid, ketoprofen, and valethamate) for ion-exchange retention and one analyte (prednisone) for reversed-phase retention.
The below steps are performed by the Andrew+, unless specified.
The Oasis 2x4 SPE Method Development Workflow (Figure 1) is automated using the Andrew+ Pipetting Robot with labware that are commonly used in laboratory settings for convenient setup and execution.
The solvents, reagents, and the spiked human blood plasma samples required for the workflow are prepared manually prior to the execution of the Andrew+ Protocol.
Figure 3 shows the recovery of analytes from spiked human blood plasma samples for imipramine, 1-decanesulfonic acid, ketoprofen, and valethamate that are retained by ion-exchange MCX, WAX, MAX, and WCX sorbents respectively and prednisone that is retained by reversed-phase mechanism by all four sorbent chemistries using the Andrew+ Automated Oasis 2x4 SPE Sorbent Selection Method, demonstrating quick and easy sorbent selection method development, combined with good reproducibility and saving approximately two-to-three hours of manual effort.
An automated mixed-mode SPE sorbent selection method development workflow is demonstrated using the Andrew+ Pipetting Robot for quick, reliable, and easy method optimization of the analyte recovery, combined with good reproducibility using mixed-mode SPE.
720007302, June 2021