Atmospheric solids analysis probe

One of the most significant developments in mass spectrometry in the recent years is the introduction of a new class of ionization methods where samples in either solid or liquid state can be directly ionized in their native environment under ambient conditions (rather than inside a mass spectrometer) without any sample preparation. This new class of ionization methods is often referred to as ambient ionization methods [1,2], Because these methods generally ionize analytes on the surface or near the surface of the samples at atmospheric pressure, they have also been called atmospheric pressure surface sampling/ionization methods or direct/open air ionization methods [3], Since the first reports on ambient ionization with desorption electrospray ionization (DESI) [4] and direct analysis in real time (DART) [5], numerous reports have been published on the applications of these new ionization methods as well as the introduction of many related ambient ionization methods such as desorption atmospheric pressure chemical ionization (DAPCI) [6], atmospheric solid analysis probe (ASAP) [7], and electrospray-assisted laser desorption/ionization (ELDI) [8], Recently, two reviews of the various established and emerging ambient ionization methods have been published [2,3],... 

A new generation of mass spectrometer inlets allow for direct sampling of a substrate under ambient conditions. Theoretically, this eliminates the need for any sample preparation. Examples include direct analysis in real time (DART) and desorption electrospray ionization (DESI), as well as desorption atmospheric-pressure chemical ionization (DAPCI) and atmospheric solids analysis probe (ASAP). These techniques utilize a source of energy interacting directly with a sample surface at ambient pressure, causing molecules of interest to desorb, ionize, and be sampled by a mass spectrometer. 

McEwen, C. Gutteridge, S. Analysis of the inhibition of the ergosterol pathway in fungi using the atmospheric solids analysis probe (ASAP) method. / Am. Soc. Mass Spectwm. 2007, 18, 1274-1278. 

Trimpin, S., Wijerathne, K., and McEwen, C.N. (2009) Rapid methods of polymer and polymer additives identification Multi-sample solvent-free MALDl, pyrolysis at atmospheric pressure, and atmospheric solids analysis probe mass spectrometry. Anal. Chim. Acta, 654, 20-25. 

McEwen, C., Gutteridge, S. (2007) Analysis of the Inhibition of the Ergosterol Pathway in Fungi Using the Atmospheric Solids Analysis Probe (ASAP) Method. J. Am. Soc. Mass Spectrom. 18 1274-1278. 

Ambient MS is another advance in the field. It allows the analysis of samples with little or no sample preparation. Following the introduction of desorption electrospray ionization (DESI) [108,109], direct analysis in real time (DART) [110], and desorption atmospheric pressure chemical ionization (DAPCI) [111, 112], a number of ambient ionization methods have been introduced. They include electrospray-assisted laser desorption/ionization (ELDI) [113], matrix-assisted laser desorption electrospray ionization (MALDESI) [114], atmospheric solids analysis probe (ASAP) [115], jet desorption ionization (JeDI) [116], desorption sonic spray ionization (DeSSI) [117], field-induced droplet ionization (FIDI) [118], desorption atmospheric pressure photoionization (DAPPI) [119], plasma-assisted desorption ionization (PADI) [120], dielectric barrier discharge ionization (DBDI) [121], and the liquid microjunction surface sampling probe method (LMJ-SSP) [122], etc. All these techniques have shown that ambient MS can be used as a rapid tool to provide efficient desorption and ionization and hence to allow mass spectrometric characterization of target compounds. 

Q IMS/MS Applied to Direct Ionization Using the Atmospheric Solids Analysis Probe Method... 

Numerous ambient direct ionization methods have been introduced for use with mass spectrometry over the last several years.< - °) A major advantage of these methods is speed of analysis, which is achieved not only by the fast insertion and ionization of the sample, but by the elimination of most sample preparation and chromatographic separations. However, this presents a problem in materials analysis and for mixtures in general because of the complexity of the mass spectra that result from direct analysis of complex mixtures. The atmospheric solids analysis probe (ASAP)< > mass spectrometry (MS) method offers some separation related to volatility by control of the heated gas used to effect vaporization, but this is not sufficient for many mixtures. Ion mobility spectrometry (IMS) offers rapid gas-phase separation of ions based on differences in charge state and collision cross section (CCS) (size/shape). Here we explore the utility of a commercial IMS/MS instrument with ASAP sample introduction for analysis of complex mixtures. 

After presenting an overview chapter and the fundamentals, the book focuses on instrumentation and ionization sources. It describes an ion-mobility-capable quadrupole time-of-flight mass spectrometer, the differential mobility analyzer, a cryogenic-temperature ion mobility mass spectrometer, the atmospheric solids analysis probe method, and laserspray ionization. In the final applications-oriented chapters, the contributors explore how homebuilt and commercial instruments using electrospray ionization and matrix-assisted laser desorption/ionization (MALDl) methods are employed to solve biological and synthetic issues. 

Discusses novel methods and instruments, including lasersprav ionization and atmospheric solids analysis probe... 

Barr re et al. extended the use of atmospheric solid analysis probe (ASAP) combined with travelling wave ion mobility mass spectrometry (TWIM-MS) for the... 

DGE a AC AMS APCI API AP-MALDI APPI ASAP BIRD c CAD CE CF CF-FAB Cl CID cw CZE Da DAPCI DART DC DE DESI DIOS DTIMS EC ECD El ELDI EM ESI ETD eV f FAB FAIMS FD FI FT FTICR two-dimensional gel electrophoresis atto, 10 18 alternating current accelerator mass spectrometry atmospheric pressure chemical ionization atmospheric pressure ionization atmospheric pressure matrix-assisted laser desorption/ionization atmospheric pressure photoionization atmospheric-pressure solids analysis probe blackbody infrared radiative dissociation centi, 10-2 collision-activated dissociation capillary electrophoresis continuous flow continuous flow fast atom bombardment chemical ionization collision-induced dissociation continuous wave capillary zone electrophoresis dalton desorption atmospheric pressure chemical ionization direct analysis in real time direct current delayed extraction desorption electrospray ionization desorption/ionization on silicon drift tube ion mobility spectrometry electrochromatography electron capture dissociation electron ionization electrospray-assisted laser desorption/ionization electron multiplier electrospray ionization electron transfer dissociation electron volt femto, 1CT15 fast atom bombardment field asymmetric waveform ion mobility spectrometry field desorption field ionization Fourier transform Fourier transform ion cyclotron resonance... 

There are some variants that have emerged in the wake of DESI. By replacing the electrospray emitter by a metal needle and allowing solvent vapor into the coaxial gas flow desorption APCI (DAPCI) can be performed [106], Other versions are atmospheric-pressure solids analysis probe (ASAP) where a heated gas jet desorbs the analyte, which is subsequently ionized by a corona discharge [107], and electrospray-assisted laser desorption/ionization (ELDI) where a laser ablates the analyte and charged droplets from an electrospray postionizes the desorbed neutrals [108],... 

McEwen et al. have utilized another ambient technique called atmospheric pressure solids analysis probe (ASAP) [84,85] and interfaced it with TWIM-MS [86], This source is now available commercially on the Synapt instrument. They have used m/z vi drift time plots to define compound classes in CTude oil analysis and to resolve isobaric compounds. Excellent agreement was demonstrated for drift times obtained from standards run individually and doped into the crude oil mixture. This work demonstrates the utility of mobility experiments to provide a degree of separation and classification in the study of very complex mixtures where chromatographic separation is either not possible or too time consuming. 

Smith, M.J.P., Cameron, N.R., and Mosely, J.A. (2012) Evaluating Atmospheric pressure Solids Analysis Probe (ASAP) mass spectrometry for the analysis of low molecular weight synthetic polymers. Analyst, 137,... 

Lloyd, J. A. Harron, A. R McEwen, C., Combination Atmospheric Pressure Solids Analysis Probe and Desorption Electrospray Ionization Mass Spectrometry Ion Source. Anal. Chem. 2009, 81, 9158-9162. 

ASAP Atmospheric pressure solids analysis probe Evaporation of solids in hot gas stream and ionization by corona discharge [55]... 

C. N. McEwen, R. G. McKay, and B. S. Larsen. Analysis of Solids, Liquids, and Biological Tissues Using Solids Probe Introduction at Atmospheric Pressure on Commercial LC/MS Instruments. Anal. Chem., 77(2005) 7826-7831. 

The advantages of this technique are that they are applicable to probes in ultra high vacuum, where any impurities are excluded, and also to samples at atmospheric pressure. The diameter of the evaporated cavity can be varied between 10 jam and 1 mm, and the quantity of the evaporated material may be less than 10" g. Solids in any desired form, crystalline or powered, are accessible to analysis. 

McEwen, C. N., McKay, R. G., and Larsen, B. S. (2005). Analysis of solids, liquids, and biological tissues using solids probe introduction at atmospheric pressure on commercial LC/MS instruments. Anal. Chem. 77 7826-7831. 

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