DESI Spray Stability in the Negative Ion Mode Is Dependent on Relative Humidity

  • Clara L. Feider
  • Rachel J. DeHoog
  • Marta Sans
  • Jialing Zhang
  • Anna Krieger
  • Livia S. EberlinEmail author
Application Note


Ambient ionization mass spectrometry (MS) techniques, such as desorption electrospray ionization (DESI), have been increasingly used due to their simplicity, minimal sample preparation requirements, and potential applications in the field and the clinic. However, due to their intrinsic nature, the performance of these methods is susceptible to variations in ambient conditions. Here, we present data that suggests DESI-MS analysis becomes inconsistent below a relative humidity (RH) level of ~ 35%. At low RH, we hypothesize that the DESI spray is subjected to frequent electrical discharges, resulting in unstable ionization and atypical mass spectra. Consequentially, poor image quality is observed when used for tissue imaging. Our results suggest that RH control should be considered in DESI-MS experiments to assure data quality.

Graphical Abstract


Desorption electrospray ionization Mass spectrometry imaging Humidity Data quality 



Support from the NIH (R00CA190783) and the Welch Foundation (F-1895) is gratefully acknowledged. We thank Collin Davies from Prof. Richard M. Crooks research group (UT Austin) and Dr. Sankha Basu from Prof. Nathalie Y.R. Agar’s research group (Harvard Medical School) for fruitful discussions.

Supplementary material

13361_2018_2105_MOESM1_ESM.docx (1 mb)
ESM 1 (DOCX 1.04 mb)


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Copyright information

© American Society for Mass Spectrometry 2018

Authors and Affiliations

  1. 1.Department of ChemistryThe University of Texas at AustinAustinUSA

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