Surface-Modified Wooden-Tip Electrospray Ionization Mass Spectrometry for Enhanced Detection of Analytes in Complex Samples

Anal Chem. 2018 Feb 6;90(3):1759-1766. doi: 10.1021/acs.analchem.7b03675. Epub 2018 Jan 17.

Abstract

Replacement of capillary with solid substrates for sample loading and ionization has created many new possibilities for electrospray ionization mass spectrometry (ESI-MS). Surface modification is an attractive strategy to enhance the analytical capability of solid-substrate ESI-MS and allow understanding the relationship between surface activity of solid substrates and analytical properties. In this study, we performed surface modification of wooden tips with hydrophobic (-C18), basic (-NH2), and acidic (-SO3H) functional groups and applied various sampling methods, i.e., extractive sampling and direct loading, to comprehensively investigate the analytical properties of solid-substrate ESI-MS. Our results showed that, for the direct loading method, analytes with weak interactions with solid-substrate surface could be readily sprayed out for detection. While for the extractive sampling method, analytes strongly retained on solid-substrate surface could be selectively enriched and detected, and a washing step after sample loading could effectively remove unbound components for reducing interference. Overall, the insights on the effects of surface-analyte interactions on the analytical features obtained in this study could aid the development of surface-modified strategies for enhancing the analytical capability of solid-substrate ESI-MS.

Publication types

  • Research Support, Non-U.S. Gov't