Laser spray-assisted

Currently, API based LC-MS interfaees, i.e., ESI and APCI, are the most widely applied approaches, while other interfaces like TSP and Cf-FAB can be considered obsolete. Despite the successes of these commercially available interfaces, research towards newer and/or advanced interface strategies continues. These research efforts comprise among others the implementation of on-line LC-MS using matrix-assisted laser desorption/ionization (Ch. 5.9), the sonic spray (Ch. 5.7.1), and the laser spray (Ch. 5.7.2) interface. 

In the recent past, a nnmber of laser-based interface approaches were described. The role of the laser was different from providing heat for the mobile-phase nebnlization and snbseqnent solvent evaporation in the laser spray interface (Ch. 5.7.2), via laser-indnced mnltiphoton ioitization, to matrix-assisted laser desorption ionization (MALDl). 

Other processes investigated for planar SOFC fabrication include electrostatic-assisted vapour deposition, vapour phase electrolytic deposition, vacuum evaporation, laser spraying, transfer printing, sedimentation method, and plasma metal organic chemical vapour deposition. 

Fast atom bombardment (FAB) Plasma desorption (PD) Liquid secondary-ion mass spectrometry (LSIMS) Thermospray (TSP)/plasmaspray (PSP) Electrohydrodynamic ionisation (EHI) Multiphoton ionisation (MPI) Atmospheric pressure chemical ionisation (APCI) Electrospray ionisation (ESI) Ion spray (ISP) Matrix-assisted laser desorption/ionisation (MALDI) Atmospheric pressure photoionisation (APPI) Triple quadrupole (QQQ) Four sector (EBEB) Hybrid (EBQQ) Hybrid (EB-ToF, Q-ToF) Tandem ToF-ToF Photomultiplier... 

For non-volatile sample molecules, other ionisation methods must be used, namely desorption/ionisation (DI) and nebulisation ionisation methods. In DI, the unifying aspect is the rapid addition of energy into a condensed-phase sample, with subsequent generation and release of ions into the mass analyser. In El and Cl, the processes of volatilisation and ionisation are distinct and separable in DI, they are intimately associated. In nebulisation ionisation, such as ESP or TSP, an aerosol spray is used at some stage to separate sample molecules and/or ions from the solvent liquid that carries them into the source of the mass spectrometer. Less volatile but thermally stable compounds can be thermally vaporised in the direct inlet probe (DIP) situated close to the ionising molecular beam. This DIP is standard equipment on most instruments an El spectrum results. Techniques that extend the utility of mass spectrometry to the least volatile and more labile organic molecules include FD, EHD, surface ionisation (SIMS, FAB) and matrix-assisted laser desorption (MALD) as the last... 

The use of diisoprop anolamine in the synthesis of the hyperbranched poly-esteramide resins has led to defined molecules according to the predicted structures (Fig. 7) as confirmed by MALDI-TOF (Matrix Assisted Laser Desorption Ionization - Time Of Flight) and ESI (Electro Spray Ionization) mass spectra... 

Vivas, N. et al.. Differentiation of proanthocyanidin tannins from seeds, skins and stems of grapes Vitis vinifera) and heartwood of Quebracho (Schinopsis balansae) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and thioacidolysis/liquid chromatography/electro-spray ionization mass spectrometry. Anal Chim. Acta, 513, 247, 2004. 

Krueger, C.G., Vestling, M.M., and Reed, J.D., Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry of anthocyanin-polyflavan-3-ol oligomers in cranberry fruit (Vacci-nium macrocarpon. Ait.) and spray-dried cranberry juice, ACS Symp. Ser., 886, 232, 2004. 

Mass spectrometry (MS) is a very sensitive method of determining the mass of native proteins, as well as their purity. The two most common techniques are ESI-MS (electron spray ionization-MS) and MALDI-TOF-MS (matrix-assisted laser... 

A visualization study of fuel atomization using a pulsed laser holography/photography technique indicates that basic spray formation processes are the same for both a coal-derived synthetic fuel (SRC-II) and comparable petroleum fuels (No. 2 and No. 6 grade). Measurements were made on both pressure swirl and air assisted atomizers in a cold spray facility having well controlled fuel temperature. Quality of the sprays formed with SRC-II was between that of the No. 2 and No. 6 fuel sprays and was consistent with measured fuel viscosity. Sauter mean droplet diameter (SMD) was found to correlate with fuel viscosity, atomization pressure, and fuel flow rate. For all three fuels, a smaller SMD could be obtained with the air assisted than with the pressure swirl atomizer. 

Fig. 1 Schematic representation of a mass spectrometer depicting its main components and the different modes used. Abbreviations DIP direct insertion probe DEP direct exposure probe GC gas chromatography LC liquid chromatography CE capillary chromatography TEC thin-layer chromatography FEE field-flow fractionation APCI atmospheric pressure ionization El electron impact Cl chemical ionization FAB fast-atom bombardment PD plasma desorption MALDI matrix-assisted laser desorption ionization ED laser desorption TSP thermospray ESI electron spray ionization HSI hypherthermal surface ionization Q quadropole QQQ triple quadropole TOE time-of-fiight FTMS Fourier transform mass spectrometer IT ion trap EM electrom multiplier PM photomultiplier ICR ion cyclotron resonance.

Mass spectrometers see Chapter 7) coupled with gas and liquid chromatographs (see Chapter 6) afe powerful qualitative and quantitative analytical tools that are widely used to measure hormones. Technical advancements in mass spectrometry have resulted, in the, development of matrix-assisted laser desorption/ioiiizati,6n (MALDI) and electro-spray ionization techiiiques that allow siequencing of peptides and mass determination of piconiole quantities of analytes. 

Several ionization methods have been applied for CE-MS couphng. Matrix-assisted laser desorption ionization (MALDI), continuous flow fast atom bombardment (FAB), laser vaporization ionization with UV laser, sonic spray ionization and electrospray ionization (ESI) have all been used for coupling CE to MS. However, ESI is now undoubtedly the most widely used ionization technique, employing numerous analyzers including quadrupoles, magnetic sector, Fourier transform ion cyclotron resonance, time-offlight and trapping devices. However, quad-rupole detectors have predominantly been applied in CE-MS [6-8]. 

Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry of Anthocyanin-poly-flavan-3-ol Oligomers in Cranberry Fruit Vaccinium macrocarpon. Ait.) and Spray-Dried Cranberry Juice... 

The techniques of matrix-assisted laser desorption/ ionization-time of flight (MALDI-TOF) and electro-spray/ionization (ESI) have revolutionized biological MS since 1989. All state-of-the-art biochemistry and biology laboratories possess at least one of these ionization techniques and, in general, have access to both of them. Both ionization techniques are applicable to peptides and proteins, DNA and RNA, glycoconjugates, and synthetic polymers. 

In the first chapter of this book, an overview of CVD techniques has been given, and more detailed descriptions can be found in several textbooks [9, 10]. Many different CVD reactors have been used for the deposition of conducting films, i.e., thermal, UV-enhanced CVD (UVCVD), laser-assisted CVD (LACVD), plasma-enhanced CVD (PECVD) and metal-organic CVD (MOCVD). In addition, two techniques were included, which are not typically part of CVD, chemical transport and spray pyrolysis. 

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