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Desorption electrospray ionization (DESI) is an ambient ionization technique that can be coupled to mass spectrometry (MS) for chemical analysis of samples at atmospheric conditions. Coupled ionization sources-MS systems are popular in chemical analysis because the individual capabilities of various sources combined with different MS systems ...
Extractive electrospray ionization is a spray-type, ambient ionization method that uses two merged sprays, one of which is generated by electrospray. [ 49 ] Laser-based electrospray-based ambient ionization is a two-step process in which a pulsed laser is used to desorb or ablate material from a sample and the plume of material interacts with ...
Nanospray desorption electrospray ionization (nano-DESI) is an ambient pressure ionization technique used in mass spectrometry (MS) for chemical analysis of organic molecules. [1] In this technique, analytes are desorbed into a liquid bridge formed between two capillaries and the sampling surface. [ 2 ]
The two primary methods of ionization for mass analysis used in droplet-based microfluidics today are matrix-assisted laser desorption/ionization [241] [242] and electrospray ionization . [63] Additional methods for coupling, such as (but not limited to) surface acoustic wave nebulization ( SAWN ), [ 243 ] and paper-spray ionization onto ...
Molecular ion beam deposition employs electrospray ionization or MALDI sources. [3] The ions are then accelerated, focused or deflected using high voltages or magnetic fields. Optional deceleration at the substrate can be employed to define the deposition energy. This energy usually ranges from a few eV up to a few keV. [3]
DESI and DART are considered as pioneer techniques in the field of ambient ionization, [4] since they operate in the open laboratory environment and do not require sample pretreatment. [5] [6] In contrast to the liquid spray used by DESI, the ionizing gas from the DART ion source contains a dry stream containing excited state species.
Ambient ionization techniques are attractive for many samples for their high tolerance to complex mixtures and for fast testing. EESI has been employed for the rapid characterization of living objects, [ 10 ] native proteins , [ 11 ] and metabolic biomarkers .
The chemical ionization process generally imparts less energy to an analyte molecule than does electron impact (EI) ionization, resulting in less fragmentation [2] and usually a simpler spectrum. The amount of fragmentation, and therefore the amount of structural information produced by the process can be controlled to some degree by selection ...