CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

An investigation on the mechanism of sublimed DHB matrix on molecular ion yields in SIMS imaging of brain tissue

Masoumeh Dowlatshahi Pour (Institutionen för kemi och kemiteknik, Analytisk kemi) ; Per Malmberg (Institutionen för kemi och kemiteknik, Analytisk kemi) ; Andrew G Ewing (Institutionen för kemi och kemiteknik, Analytisk kemi ; Institutionen för kemi och molekylärbiologi)
Analytical and Bioanalytical Chemistry (1618-2642). Vol. 408 (2016), 12, p. 3071-3081.
[Artikel, refereegranskad vetenskaplig]

We have characterized the use of sublimation to deposit matrix-assisted laser desorption/ionization (MALDI) matrices in secondary ion mass spectrometry (SIMS) analysis, i.e. matrix-enhanced SIMS (ME-SIMS), a common surface modification method to enhance sensitivity for larger molecules and to increase the production of intact molecular ions. We use sublimation to apply a thin layer of a conventional MALDI matrix, 2,5-dihydroxybenzoic acid (DHB), onto rat brain cerebellum tissue to show how this technique can be used to enhance molecular yields in SIMS while still retaining a lateral resolution around 2 mu m and also to investigate the mechanism of this enhancement. The results here illustrate that cholesterol, which is a dominant lipid species in the brain, is decreased on the tissue surface after deposition of matrix, particularly in white matter. The decrease of cholesterol is followed by an increased ion yield of several other lipid species. Depth profiling of the sublimed rat brain reveals that the lipid species are de facto extracted by the DHB matrix and concentrated in the top most layers of the sublimed matrix. This extraction/concentration of lipids directly leads to an increase of higher mass lipid ion yield. It is also possible that the decrease of cholesterol decreases the potential suppression of ion yield caused by cholesterol migration to the tissue surface. This result provides us with significant insights into the possible mechanisms involved when using sublimation to deposit this matrix in ME-SIMS.

Nyckelord: ME-SIMS mechanism, Cholesterol migration, MS imaging, desorption/ionization mass-spectrometry, tof-sims, sample preparation, maldi-ms, enhancement, sensitivity, discovery, surface, lipids, beams, Biochemistry & Molecular Biology, Chemistry

Denna post skapades 2016-05-25. Senast ändrad 2016-05-27.
CPL Pubid: 236884


Läs direkt!

Länk till annan sajt (kan kräva inloggning)

Institutioner (Chalmers)

Institutionen för kemi och kemiteknik, Analytisk kemi
Institutionen för kemi och molekylärbiologi (GU)


Biokemi och molekylärbiologi

Chalmers infrastruktur