DESI Measurement Services
Desorption Electrospray Ionisation (DESI) is a highly sensitive surface mass spectrometry technique capable of analysing a wide range of surfaces under ambient conditions.
DESI is an ambient mass spectrometry development from the Cooks group at Purdue [Science, 306, 471 (2004)]. It uses an electrospray source of aqueous spray droplets to desorb ions from a sample surface and these ions are analysed in a standard electrospray mass spectrometer. The technique has the advantages of directly analysing a surface coupled with MS/MS capability under ambient conditions. It has been shown to be possible to analyses a wide range of analytes: amino acids; peptides; proteins; drug molecules; explosives and polymers, directly from everyday surfaces such as fabrics, plants, tissue and blood. A recent review paper from NPL describes the use of ambient mass spectrometries for forensics. Present DESI capability at NPL allows better than 15% repeatability, lateral imaging of 150 μm resolution and extremely high mass resolution of < 100,000 u using a Thermo Velos LTQ Orbitrap MS.
We are also keen to develop other ambient mass spectrometry techniques and presently have AP-MALDI, plasma desorption ionisation (PADI) MS (M McCoustra et al, Anal. Chem. 2007; 79, 1447) and extractive electrospray ionisation (EESI) MS (R Zenobi et al, Anal. Chem. 2007; 79, 6094) available at NPL.
Download poster detailing DESI applications entitled 'Applications of DESI for direct ambient surface analysis' (
PDF 521 KB)
Contact
Customer Service tel: +44 20 8943 8637
E-mail: nanoanalysis_enquiries@npl.co.uk