Polymer-Based Metal Nano-Coated Disposable Target for Matrix-Assisted and Matrix-Free Laser Desorption/Ionization Mass Spectrometry.

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July 15, 2016

Authors

Stefan Bugovsky1, Wolfgang Winkler1, Werner Balika2, Manfred Koranda2, Günter Allmaier1

Organizations

Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria
Sony DADC BioScience Austria, Anif, Austr

Abstract

The ideal MALDI/LDI mass spectrometry sample target for an axial TOF instrument possesses a variety of properties. Primarily, it should be chemically inert to the sample, i.e. analyte, matrix and solvents, highly planar across the whole target, without any previous chemical contact and provide a uniform surface to facilitate reproducible measurements without artifacts from previous sample or matrix compounds. This can be hard to achieve with a metal target, which has to be extensively cleaned every time after use. Any cleaning step may leave residues behind, may change the surface properties due to the type of cleaning method used or even cause microscopic scratches over time hence altering matrix crystallization behavior. Alternatively, use of disposable targets avoids these problems. As each possesses the same surface they therefore have the potential to replace the conventional full metal targets so commonly employed. Furthermore, low cost single-use targets with high planarity promise an easier compliance with GLP guidelines as they alleviate the problem of low reproducibility due to inconsistent sample/matrix crystallization and changes to the target surface properties. In our tests, polymeric metal nano-coated targets were compared to a stainless steel reference. The polymeric metal nano-coated targets exhibited all the performance characteristics for a MALDI MS sample support, and even surpassed the – in our lab commonly used – reference in some aspects like limit of detection. The target exhibits all necessary features such as electrical conductivity, vacuum, laser and solvent compatibility.

CovalX Technology Used (Click each option to learn more)

HM1

Outcomes

To analyze the glycoprotein IgM, a mass spectrometer modified with a CovalX HM1 detection system was used. Prior to analysis, Angiotensin II solutions were mixed in an Eppendorf tube with equal amounts of CHCA matrix. 1 μL of this mixture was pipetted out onto the target and allowed to dry at room temperature.The spectra obtained from placing the sample on DPT showed the predicted isotopic pattern that had been found during theoretical calculations.