Czech Society for Mass Spectrometry

(5th C4th Conference of the Czech Society for Mass Spectrometryonference of the Czech Society for Mass Spectrometry - PL-2)
Desorption nanoelectrospray: a story of one ion source

Karel Lemr ^1 *

1. Univerzita Palackého v Olomouci

Abstract

In 2004 desorption electrospray (DESI) opened the era of ambient ionization techniques. DESI was soon followed by direct analysis in real time (DART, 2005) and more than 30 ion sources exist nowadays. The ambient ionization occurs under atmospheric pressure and none or only minimal sample preparation is required. Major ambient sampling processes cover liquid extraction (spray desorption, liquid microjunction, substrate spray), thermal/chemical desorption and laser desorption. For example drug or forensic analysis, metabolomics, protein analysis, food quality control and mass spectrometry imaging were carried out using these techniques.

In 2006 we designed desorption nanoelectrospray (nanoDESI). Primary charged droplets are generated by a nanoelectrospray tip (2 μm I.D.) without assistance of nebulizing gas (although this gas is considered to be essential for DESI). Further development of nanoDESI consisted in the improvement of robustness and later on in its coupling with a high resolution instrument which has facilitated analyte identification. Ion formation was investigated and high tolerance to salt in a sample was proved. NanoDESI was applied e.g. in pharmaceutical analysis, identification of anthocyanins in wine and in chiral analysis of pharmaceuticals in blood (diastereoisomers were generated directly in the source). Recently, its applicability in mass spectrometry imaging was tested. Surface resolution better than 50 μm was demonstrated using Rhodamine B patterns. Repeated imaging scans of the same surface area were possible as low flow rate of spray liquid reduced undesirable washing effects. Another application, tissue imaging, is under investigation.

* Corresponding author: Karel.Lemr@upol.cz

References

1. Ranc V. et al.: Chem. Listy 101, 524-529 (2007).
2. Ranc V. et al.: Eur. J. Mass Spectrom. 14, 411-417 (2008).
3. Hartmanová L. et al: Analyst in press (2016).

Acknowledgement:

Many thanks to all my colleagues that “wrote” this story. Financial support by the Czech Science Foundation is acknowledged (project P206/12/1150).