By Agnieszka Sitarska
Choosing a method and developing a protocol for small molecule LC-MSMS sample preparation can be a complex process. An effective shortcut is to use an extraction plate built for automation. With fewer processing steps and an automation-ready format, the use of extraction plate technology can help make tedious LC-MS sample prep processes more routine, whether it’s the analysis of testosterone in serum or anti-depressants in whole blood.
Boost your LC-MS/MS productivity with AC Extraction Plate from Tecan
Sample preparation prior to LC-MS can be a complex process that can introduce error, as well as consuming valuable time and resources. The best way to save time, ease your workload and ensure success is to minimize the number of preparation steps. An extraction plate can provide a rapid means of purifying and concentrating analytes, in a multi-well format that is amenable to automation.
Using an automated extraction plate can simplify your LC-MS sample prep routine for apolar small molecules, such as vitamin D, certain therapeutic drugs and testosterone.
For example, the AC Extraction Plate from Tecan* has a special immobilized extraction coating (called TICE™) that enables a straightforward three-step “pipette and shake” process. The three simplified steps include extraction of analyte from one of a range of biological fluids, followed by washing to remove matrix materials, and finally elution.
This eliminates the need for sample transfers, vacuum systems, filtration, centrifugation, and solvent evaporation steps. The resulting eluate is so pure that it can be injected directly into an LC-MS system for analysis.
When using LC-MSMS for diagnostic analysis, the results need to be absolutely consistent – from day to day, operator to operator, and lab to lab. Standardization is the key to success.
Sample preparation is easily standardized and automated using an extraction plate to eliminate random errors and increase consistency of results. It is important to choose an extraction plate that offers an open and ANSI/SLAS standard format that can be applied to sample preparation for a broad range of small molecule analytes from biological fluids.
Using this type of extraction plate, you’ll have a convenient, automation-friendly solution that can handle almost any LC-MS sample preparation challenge. In addition you should be able to use it immediately, without the need for conditioning or other pretreatments.
Routine diagnostic analysis of testosterone by LC-MS/MS requires rapid and reliable extraction to obtain a sample that is pure enough for direct injection. For successful application in a busy clinical lab, the method also needs to be sensitive, easy to use, cost-effective and readily automatable.
Testosterone is a thermally stable, non-polar, uncharged steroid (Log P = 3.32) with a molecular weight of 288.42. Extraction protocols that work particularly well with such non-polar small molecules (<1,000 molecular weight) include liquid-liquid extraction (LLE), supported-liquid extraction (SLE) and the AC Extraction Plate.
To choose between these options, as well as a few less suitable options such as protein precipitation and solid-phase extraction, three key parameters to consider are:
Taking all of these factors into account, the AC Extraction Plate is an excellent choice for testosterone sample preparation prior to LC-MS/MS diagnostic analysis. An optimized and extensively validated method (1) delivers excellent precision, accuracy and robustness, making it a successful alternative to the automated immunoassays commonly used.
As illustrated by this data driven selection process, AC Extraction Plate offers an easy and flexible sample extraction solution that can significantly boost your productivity. It is a perfect match to the Tecan Freedom EVO and Fluent liquid handling platforms.
Could AC Extraction Plate* be the sample preparation solution you’ve been searching for?
* for research use only. Not for use in diagnostic procedures.
Tecan would like to thank Judith Stone, Ph.D., MT(ASCP), DABCC for technical consultation about sample preparation for LC-MSMS. Judith Stone is the senior clinical laboratory scientist specialist at the University of San Diego toxicology laboratory in the Center for Advanced Laboratory Medicine.
1. Automated Sample Preparation Enables LC-MS/MS as a Routine Diagnostic Analysis for Serum Testosterone. Judith A. Stone, Dave R. van Staveren, Robert L. Fitzerald, Journal of Applied Laboratory Medicine: An AACC Publication. DOI: 10.1373/jalm.2016.022772. Published online May 2017.
2. Application Note: Tecan AC Extraction Plate. Automated sample preparation for the determination of testosterone in serum by LC-MSMS.