Mass spectrometry, electrospray ionization emitter

Electrospray ionization-mass spectrometry (ESI-MS) Electrospray mass spectrometry Electrospray emitter on-chip Chip electrospray mass spectrometry... 

A microcapillary trap cartridge-microcapillary high-performance liquid chromatography electrospray ionization emitter device capable of peptide tandem mass spectrometry at the attomole level on an ion trap mass spectrometer with automated routine operation. Rapid Common. Mass Spectrom. 2003, 77(18), 2093-2098. 

Although electrospray ionization and matrix-assisted laser desorption ionization allow to transfer much larger ions into the gas phase, it is FD that can be regarded the softest ionization method in mass spectrometry. [27,74] This is mainly because the ionization process itself puts no excess energy into the incipient ions. Problems normally arise above 3000 u molecular weight when significant heating of the emitter causes thermal decomposition of the sample. 

Mass spectrometry tests were carried out using a LCQ deca XP + ion trap mass spectrometer (Thermo Finnigan, San Jose, CA, USA). The electrospray emitter tip nib structure was placed on a dedicated holder that is introduced in the inlet of the mass spectrometer. A platinum wire was subsequently inserted in the reservoir feature of the nib, and was connected at its other end on a metallic part on the holder where HV is normally applied for ionization purposes. Solutions to be analyzed were dropped in the reservoir feature using a gel-loader tip typically 5-10 pL of sample were deposited in the reservoir. Liquid was subsequently seen to fuse at the tip of the nib due to capillary action in the slot. HV was then applied, and a spray could be observed with HV values in a... 

Liljegren, G., Dahlin, A., Zettersten, C., Bergquist, J., Nyholm, L., On-line coupling of a microelectrode array equipped poly(dimethylsiloxane) microchip with an integrated graphite electrospray emitter for electrospray ionization mass spectrometry, Lab Chip, 5, 1008-1016, 2005. 

Recently, it was been shown that an electrospray emitter can be used to provide transla-tionally excited projectiles (charged microdroplets) which serve as projectiles for desorption and ionization of condensed-phase analytes present on surfaces. This hybrid technique, DESI (desorption electrospray ionization), is applicable to analysis of samples in the ambient environment. The practical advantage is that the sample can be examined directly, without any preparation hence the experiment is extremely fast (typically <5 s) and can be conducted in a high-throughput fashion and tandem mass spectrometry can be used for identification of components of complex mixtures. These features provide the speed of analysis and high chemical specificity that are needed in applications such as public safety monitoring. 

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