Search results
Results from the WOW.Com Content Network
DESI is a combination of popular techniques, such as, electrospray ionization and surface desorption techniques. Electrospray ionization with mass spectrometry was reported by Malcolm Dole in 1968, [ 8 ] but John Bennett Fenn was awarded a nobel prize in chemistry for the development of ESI-MS in the late 1980s. [ 9 ]
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.
One example is fast-atom bombardment ionization which can allow for liquid samples separated by the LC to flow into the ionization chamber and be ionized easily. [1] The most common ionization method coupled to LC is some form of spray ionization, which includes thermospray ionization and more commonly, electrospray (ESI) ionization.
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 ...
[13] [9] [2] In addition to the source geometry optimization, the electrospray solvent composition has an effect on the MALDESI signals (i.e. influencing molecular coverage and ion abundance). In a study to improve the detection of tissue-specific lipids, the electrospray parameters have been tailored for positive and negative ionization ...
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 ]
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]
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 .