About the ionization process the Edgard Var se composition Ionisation Var se File Ionization energies.svg right thumb 400px Ionization energies of neutral elements. Ionization is the physics physical process ... the bond and freeing it to move. The amount of energy required is called the ionization energy ... caught inside the electric potential barrier , releasing any excess energy. In general, ionization can be broken down into two types sequential ionization and non sequential ionization . In classical physics, only sequential ionization can take place refer to the Classical ionization Classical ionization section for more information. Non sequential ionization violates several laws of classical physics refer to the Quantum ionization Quantum ionization section. Classical ionization Applying only classical physics and the Bohr model of the atom makes both atomic and molecular ionization entirely ... without at least 13.6 eV of energy. Applying to positive ionization According to these two principles ... radiated out and the electron re enters the lowest available state. Applying to negative ionization ... with the electric potential barrier. Sequential ionization Sequential ionization is a description of how the ionization of an atom or molecule takes place. For example, an ion with a 2 charge ... , number. Quantum ionization In quantum mechanics , ionization can still happen classically, whereby ... possibility of tunnel ionization . Tunnel ionization Tunnel ionization is ionization due to quantum tunneling . In classical ionization, an electron must have enough energy to make it over the potential ... ionization When the fact that the electric field of light is an alternating electric field is combined with tunnel ionization, the phenomenon of non sequential ionization emerges. An electron that tunnels ... to further ionize the atom or molecule through high energy collisions. This additional ionization is referred to as non sequential ionization for two reasons One, there is no order to how the second ... more details
Distinguish chemical ionization Chemi ionization is the formation of an ion through the reaction of a gas phase atom or molecule with an atom or molecule in an excited state . ref GoldBookRef title chemi ionization file C01044 C01044 ref ref name Klucharev1993 citation last Klucharev first A. N. year 1993 title Chemi ionization processes journal Physics Uspekhi volume 36 pages 486 doi 10.1070 PU1993v036n06ABEH002162 ref Reactions Chemi ionization can be represented by math G M to M bullet e G math where G is the excited state species indicated by the superscripted asterisk , and M is the species that is ionized by the loss of an electron to form the Radical chemistry radical cation indicated by the superscripted plus dot . See also Penning ionization Associative ionization Charge exchange ionization References Reflist atomic physics stub Category Ion source it Ionizzazione chimica ... more details
Unreferenced date July 2008 The process of secondary ionization consists of removing a second electron from an atom or molecule when another electron has been removed before primary ionization . Category Ions Category Molecular physics Category Atomic physics Category Physical chemistry Category Quantum chemistry sci stub ... more details
Penning ionization is a form of chemi ionization , an ionization process involving reactions between neutral atoms and or molecules. ref name pmid17155624 cite journal author Arango CA, Shapiro M, Brumer P title Cold atomic collisions coherent control of penning and associative ionization journal Phys. Rev. Lett. volume 97 issue 19 pages 193202 year 2006 pmid 17155624 doi 10.1103 PhysRevLett.97.193202 ref ref name pmid17016831 cite journal author Hiraoka K, Furuya H, Kambara S, Suzuki S, Hashimoto Y, Takamizawa A title Atmospheric pressure Penning ionization of aliphatic hydrocarbons journal Rapid Commun. Mass Spectrom. volume 20 issue 21 pages 3213 22 year 2006 pmid 17016831 doi 10.1002 rcm.2706 ref The process is named after the Dutch physicist Frans Michel Penning who first reported it in 1927. ref Penning, F. M. Die Naturwissenschaften , 1927, 15 , 818. ber Ionisation durch metastabile Atome. ref Reactions Penning ionization refers to the interaction between a gas phase excited state atom or molecule G sup sup and a target molecule M resulting in the formation of a radical molecular cation M sup . sup , an electron e sup sup , and a neutral gas molecule G ref GoldBookRef title Penning gas mixture file P04476 ref math G M to M bullet e G math Penning ionization occurs when the target molecule has an ionization potential lower than the internal energy of the excited state atom or molecule. associative ionization Associative Penning ionization can also occur math G M to MG bullet e math Surface Penning ionization refers to the interaction of the excited state gas with a surface S, resulting in the release of an electron. math G S to G S e math The positive charge symbol math S math that would appear to be required for charge conservation is omitted, because S is a macroscopic surface and the loss of one electron has a negligible effect. See also Chemical ionization References reflist Category Ion source it Ionizzazione di Penning ... more details
Ionization cooling is a process by which the beam emittance of a beam of particles may be reduced . ref G.I. Budker, in Proceedings of 15th International Conference on High Energy Physics, Kiev, 1970 A.N. Skrinsky, Intersecting storage rings at Novosibirsk, in Proceedings of Morges Seminar, 1971 Report CERN D.PH II YGC mng ref In ionization cooling, particles are passed through some material. The momentum of the particles is reduced as they ionize atomic electrons in the material. Thus the normalised beam emittance is reduced. By re accelerating the beam, for example in an RF cavity, the longitudinal momentum may be restored without replacing transverse momentum. Thus overall the angular spread and hence the geometric emittance in the beam will be reduced. Ionization cooling can be spoiled by stochastic physical processes. Multiple Coulomb scattering in muons as well as nuclear scattering in protons and ions can reduce the cooling or even lead to net heating transverse to the direction of beam motion. In addition, energy straggling can cause heating parallel to the direction of beam motion. Muon cooling The primary use of ionization cooling is envisaged to be for cooling of muon beams. This is because ionization cooling is the only technique that works on the timescale of the muon lifetime. Ionization cooling channels have been designed for use in a Neutrino Factory and a Muon Collider . Muon ionization cooling is expected to be demonstrated for the first time by the Proof of Principle International Muon Ionization Cooling Experiment . Other PoP muon ionization cooling experiments have been devised. Other particles Ionization cooling has also been proposed for use in low energy ion beams and proton beams. References reflist DEFAULTSORT Ionization Cooling Category Particle accelerators Category Particle physics ... more details
Associative ionization is a gas phase reaction in which two atom s or molecule s interact to form a single product ion . ref GoldBookRef title associative ionization file A00475 ref One or both of the interacting species may have excess internal energy . For example math A B to AB bullet e math where species A with excess internal energy indicated by the asterisk interacts with B to form the ion AB sup sup . References Reflist See also Chemi ionization Penning ionization References Reflist refbegin cite journal author Jones DM, Dahler JS title Theory of associative ionization journal Phys. Rev., A volume 37 issue 8 pages 2916 2933 year 1988 month April pmid 9900022 doi 10.1103 PhysRevA.37.2916 url http link.aps.org abstract PRA v37 p2916 Cite journal last Cohen first James S. year 1976 title Multistate curve crossing model for scattering Associative ionization and excitation transfer in helium journal Physical Review A volume 13 pages 99 doi 10.1103 PhysRevA.13.99 refend atomic physics stub Category Ion source ... more details
Electron ionization EI , formerly known as electron impact is an ionization method in which energetic electron s interact with gas phase atoms or molecules to produce ion s. ref GoldBookRef title electron ionization file E01999 ref This technique is widely used in mass spectrometry , particularly for gases and volatile organic chemistry organic molecules . Principle of operation Image Schematic diagram of an EI ion source.jpg thumb right 300 px Diagram representing an electron ionization ion source The following Phase matter gas phase reaction describes the electron ionization process ref R. Davis, M. Frearson, 1987 . Mass Spectrometry Analytical Chemistry by Open Learning , John Wiley & Sons, London. ref math M e to M bullet 2e , math where M is the analyte molecule being ionized, e sup sup is the electron and M sup sup is the resulting ion . In an EI ion source , electrons are produced ... electrons, referred to as a hard ionization source, causes large fluctuations in the electric field around the neutral molecules and induces ionization and fragmentation. ref K. Robinson et al. Undergraduate ... cation products are then directed towards the mass analyzer by a repeller electrode. The ionization ... detection and signal processing, convey structural information about the analyte. The ionization ... and the analyte molecules do not transfer enough energy to cause ionization. At around 70 ..., leading to the strongest possible ionization and fragmentation. Under these conditions, about 1 in 1000 ... to the electrons and ionization efficiency decreases. Notes Reflist References refbegin cite ... Stephen J. Schrader title Interpretation of Electron Ionization Data The Odd Book publisher Not Avail ... title Theory of ionization of atoms by electron impact publisher Colorado Associated University ... title Electron impact ionization publisher Springer Verlag location Berlin year 1985 pages isbn ...&Units SI&Mask 200 Mass Spec NIST Chemistry WebBook Mass spectrometry DEFAULTSORT Electron Ionization ... more details
Adiabatic ionization is a form of ion ization in which an electron is removed from or added to an atom or molecule in its lowest energy state to form an ion in its lowest energy state. ref GoldBookRef title adiabatic ionization file A00143 ref See also Adiabatic process References Reflist atomic physics stub Category Mass spectrometry ... more details
Unreferenced stub auto yes date December 2009 File Impact ionization schematic.svg thumb 350px An example of impact ionization in a semiconductor. Impact ionization is the process in a material by which one energetic charge carrier can lose energy by the creation of other charge carriers. For example, in semiconductors, an electron or hole with enough kinetic energy can knock a bound electron out of its bound state in the valence band and promote it to a state in the conduction band, creating an electron hole pair. If this occurs in a region of high electrical field then it can result in avalanche breakdown . This process is exploited in avalanche diode s, by which a small optical signal is amplifier amplified before entering an external electronic circuit. In an avalanche photodiode the original charge carrier is created by the absorption of a photon . In some sense, impact ionization is the reverse process to Auger electron Auger recombination . Avalanche photodiodes APD s are used in Optical receivers before the signal is given to the receiver circuitry the photon is multiplied with the photocurrent and this increases the sensitivity of the receiver since photocurrent is multiplied before encountering of the thermal noise associated with the receiver circuit DEFAULTSORT Impact Ionization Category Semiconductors Nuclear stub de Sto ionisation lt Sm gin jonizacija ja pl Jonizacja zderzeniowa ru uk ... more details
Tunnel ionization is a process in which electron s in an atom or a molecule pass through the potential barrier and escape from the atom or molecule . In an intense electric field , the potential barrier of an atom molecule is distorted drastically. Therefore, the length of the barrier that electrons ... ionization come and go to the atom molecule in every half period. In this process, some electrons ... light . When the recombination does not occur, further ionization proceeds by collision between ... The tunneling ionization rate for the hydrogen atom in an electrostatic field using the semi ... , 2nd ed., pg 276. Tunnel Ionization probability for H like atoms considering potential well was initially proposed by Keldysh Sov. Phys. JETP, 1965 . Theory extended to ionization from excited electronic ... et al. ADK, JETP, 1986 . Tunneling Ionization of atoms was first observed experimentally by Chin ... Augst et al. J. Opt. Soc. Am, 1991 etc. Theoretical and Experimental works regarding ionization related ... work of ADK is so far the most valid and highly appreciated theory. Physical Process Tunneling Ionization ... of tunnel ionization. Notation math E a math is the characteristic atomic electric field the electric field at the bohr radius math omega a math is the frequency associated with the ionization ... DC Tunneling Ionization Tunneling ionization from the ground state of a Hydrogen atom in an electrostatic ... system that given it proper exponential dependence of the ionization rate on the applied external field. When math E E a math , the ionization rate for this system is given by math w 4 omega a frac ... epsilon 0 2 hbar 3 math . The ionization rate is the total probability current through the outer classical ... wavefunction though the suppressed coulomb potential barrier. AC Electric Field The ionization rate ... limit, as the DC ionization rate averaged over a single period of the electric fields oscillation ... atom by A.D.K.. reflist DEFAULTSORT Tunnel Ionization Category Ions Category Atomic physics zh ... more details
Chemical ionization CI is an ionization technique used in mass spectrometry . ref Munson, M.S.B. Field, F.H. J. Am. Chem. Soc. 1966 , 88 , 2621 2630. http dx.doi.org 10.1021 ja00964a001 Chemical Ionization ... of electron ionization and chemical ionization mass spectrometry journal Recent Prog. Horm. Res ... Dougherty RC title Negative chemical ionization mass spectrometry applications in environmental ... doi 10.1002 bms.1200080702 ref Chemical ionization is a lower energy process than electron ionization ... reagent gas molecules will create an ionization plasma physics plasma . Positive and negative ... Charge exchange ionization charge exchange Self chemical ionization occurs when the reagent ion is an ionized form of the analyte. ref Cite journal doi 10.1021 ac00226a011 title Chemical ionization ... NGI, ECNCI redirects here Negative chemical ionization NCI Chemical ionization for gas phase analysis ... described above. In order to see a response by negative chemical ionization, the analyte ... ionization . Because not all analytes can do this, using NCI provides a certain degree of selectivity that is not available with other, more universal ionization techniques EI, PCI . NCI can be used ... mass spectrometry with negative chemical ionization for exposure estimation journal Journal of Chromatography ... of plasma of wild birds through gas chromatography negative chemical ionization mass spectrometry journal ... to a gas chromatograph . Atmospheric pressure chemical ionization APCI Chemical ionization in an atmospheric pressure electric discharge is called atmospheric pressure chemical ionization . The analyte is a gas or liquid spray and ionization is accomplished using an atmospheric pressure corona discharge. This ionization method is often coupled with high performance liquid chromatography where the mobile ... ions? http www.chem.harvard.edu mass tutorials ci.html Chemical Ionization Tutorial GoldBookRef title chemical ionization in mass spectrometry file C01026 Mass spectrometry DEFAULTSORT Chemical ... more details
Technical date September 2010 In thermal ionization , also referred to as surface ionization , chemically purified material loaded onto a Electrical filament filament which is then heated to cause some of the material to be ion ized as it boils off the hot filament. Filaments are generally flat pieces of metal around 1 2mm wide, 0.1mm thick, bent into an upside down U shape and welded to steel posts that supply a current. Saha Langmuir equation The likelihood of ionisation is a function of the filament temperature, the work function of the filament substrate and the ionization energy of the chemical element element . This is summarised in the Megh Nad Saha Saha Irving Langmuir Langmuir equation ref name 1.1655755 Cite journal title The Saha Langmuir Equation and its Application journal Journal of Applied Physics date January 1968 first M. J. last Dresser coauthors volume 39 issue 1 pages 338 339 doi 10.1063 1.1655755 url http scitation.aip.org getpdf servlet GetPDFServlet?filetype pdf&id JAPIAU000039000001000338000001&idtype cvips&prog normal format PDF accessdate 2007 10 11 ref math frac Y 1 Y 0 frac g 1 g 0 exp Bigg frac phi IP kT Bigg math math frac Y 1 Y 0 math ion to neutral ratio math frac g 1 g 0 math statistical weights of ion and neutral states math phi math surface work function IP element ionization potential k Boltzmann s constant T surface temperature Thermal ionization mass spectrometry One application of thermal ionization is thermal ionization mass spectrometry ... supply, and is suitable for species with a low ionization energy, such as Strontium Sr , and Lead Pb . The disadvantages of this method stem from the maximum temperature achieved in thermal ionization ... to create atomic ions of species with a high ionization energy, such as Osmium Os , and Tungsten Hf W . Although the TIMS method can create molecular ions instead in this case, species with high ionization ... References Reflist DEFAULTSORT Thermal Ionization Category Ion source et Termoionisatsioon it Ionizzazione ... more details
morefootnotes date December 2008 The term ionization energy E sub I sub of an atom or molecule means the energy needed to remove electrons from an atom. Large atoms require low ionization energy while small atoms require high ionization energy. This quantity was formerly called ionization potential , and was at one stage measured in volts. The name ionization energy is now strongly preferred. In atomic physics the ionization energy is measured using the unit Electron volt electronvolt eV . In chemistry ... ionization energy and corresponds to the energy required to remove to infinity one mole of electrons from one mole of gaseous atoms or molecules . However it is often just called ionization energy . ref GoldBookRef title Ionization energy file I03199 ref More generally, the nth ionization energy is the energy ..., or the strength by which the electron is bound the greater the ionization energy, the more difficult it is to remove an electron. The ionization energy is, thus, an indicator of the reactivity of an element. Elements with a low ionization energy tend to be reducing agents and form cations , which in turn combine with anions to form Salt chemistry salt s. The term ionization energy is sometimes used ... from the ionization energy of the atom or molecule in question when it is in free space. So, in the case ... s law . Image BE vs Z.jpg thumb 200px Values and trends Main article Molar ionization energies of the elements Generally the n 1 th ionization energy is larger than the n th ionization energy. Always, the next ionization energy involves removing an electron from an orbital closer to the nucleus ... table cell padding 4 class wikitable sortable Successive molar ionization energies in joule ... in the successive molar ionization energies occur when passing noble gas configurations. For example, as can be seen in the table above, the first two molar ionization energies of magnesium stripping ... thumb 300px Periodic trend for ionization energy. Each period begins at a minimum for the alkali ... more details
Spark ionization also known as spark source ionization wikt deprecated deprecated is a method used to produce gas phase ion s from a solid sample. The prepared solid sample is vaporized and partially ionized by an intermittent discharge or spark. ref http www.iupac.org goldbook S05780.pdf IUPAC gold book definition ref This technique is primarily used in the field of mass spectrometry . When incorporated with a mass spectrometer the complete instrument is referred to as a spark ionization mass spectrometer or as a spark source mass spectrometer SSMS . ref cite journal author H. E. Beske, A. Hurrle and K. P. Jochum title Part I. Principles of spark source mass spectrometry SSMS year 1981 journal Fresenius Journal of Analytical Chemistry volume 309 issue 4 pages 258 261 doi 10.1007 BF00488596 ref Sample preparation Typically samples are physically incorporated into two conductive electrode s usually either carbon or silver between which a high voltage electric spark is produced, ionizing the material at the tips of the electrodes. If metals are being analyzed the sample may serve as an electrode. Technical information Mass analyzers are typically Sector instrument Mattauch Herzog geometry, and use either photosensitive plates for ion detection or linear channeltron detector arrays. References refbegin reflist refend Mass spectrometry DEFAULTSORT Spark Ionization Category Ion source it Ionizzazione a scintilla ... more details
Ambient ionization is a form of ion ization in which ions are formed outside the mass spectrometer without sample preparation or separation. ref name Cooks2006 Cite journal last1 Cooks first1 R. Graham last2 Ouyang first2 Zheng last3 Takats first3 Zoltan last4 Wiseman first4 Justin M. year 2006 title Ambient Mass Spectrometry journal Science volume 311 issue 5767 pages 1566 70 doi 10.1126 science.1119426 pmid 16543450 postscript None ref Direct analysis in real time main DART ion source Direct analysis in real time DART is an atmospheric pressure ion source that operates by exposing the sample to a gas stream typically helium or nitrogen that contains long lived electronically or excited neutral atoms , vibronically excited molecules or Metastability in molecules metastables . Excited state ... Air under Ambient Conditions ref Desorption electrospray ionization main Desorption electrospray ionization Desorption electrospray ionization DESI uses an electrospray source to create charged droplets ... using desorption electrospray ionization DESI instrumentation, mechanisms and applications in forensics ... Electrospray assisted laser desorption ionization ELDI relies on a laser to the desorption of material ... HJ, Lee CY, Yuan CH, Beech I, Sunner J title Electrospray assisted laser desorption ionization mass ... electrospray ionization MALDESI , a nitrogen laser is used to desorb material into the electrospray ... ionization MALDESI Fourier transform ion cyclotron resonance mass spectrometry journal J. Am ... ref MALDESI has been used with MALDI matrix materials. Laser ablation electrospray ionization ... author Nemes P, Vertes A title Laser Ablation Electrospray Ionization for Atmospheric Pressure ... 106 year 2007 pmid 17900146 doi 10.1021 ac071181r ref The term laserspray ionization has been used ... Ionization, a New Atmospheric Pressure MALDI Method for Producing Highly Charged Gas phase Ions ... ionization References Reflist Category Mass spectrometry ... more details
Image Plasma lamp 2.jpg thumb 300px right A plasma globe plasma lamp , illustrating a low degree of ionization ie. a partially ionized gas The degree of ionization refers to the proportion of neutral particles, such as those in a gas or aqueous solution, that are ionized into charged particles. A low degree of ionization is sometimes called partially ionized , and a very high degree of ionization as fully ionized . Ionization refers to the process whereby an atom or molecule loses an electron , resulting in two oppositely charged particles, 1 a negatively charged electron and 2 a positively charged ion . Chemistry usage The degree of ionization , or , is a way of representing the strength of an acid, often represented by the Greek letter alpha. It is defined as the ratio between the number of ionized molecules and the number of molecules dissolved in water. It can be represented as a decimal number or as a percentage. One can classify strong acids as having ionization degrees above 50 , weak acids with below 5 , and the remaining as moderate acids, at a specified molar concentration. Physics usage In gases and Plasma physics plasma , the degree of ionization refers to the proportion of neutral particles that are ionized into charged particles. For example, when electricity passes through a novelty plasma ball , perhaps 1 of the gases are ionized sometimes referred to as partially ionized . Our Sun and all stars contain largely hydrogen and helium gases, that are fully ionized into electrons, protons H sup sup and helium ions He sup sup . A gas may begin to behave like plasma when the degree of ionization is as little as 0.01 . ref Brian Chapman, Glow discharge plasmas. p49 ref Etiqueta Examen ref Shibamoto, Takayuki. Introduction to Food Toxicology, 2nd Edition. Academic Press, 2009. p17. ref History Ionized matter was first identified in a discharge tube or Crookes tube , and so described by Sir William Crookes in 1879 he called it radiant matter . ref Crookes presented ... more details
The ionization chamber is the simplest of all gas filled radiation detectors, and is used for the detection or measurement of ionizing radiation . Conventionally, the term ionisation chamber is used exclusively to describe those detectors which collect ion pairs from gases. ref cite book first Glenn F last Knoll title Radiation detection and measurement edition 3rd year 1999 location New York publisher Wiley isbn 0 471 07338 5 ref Construction and operation File Ionization chamber.svg thumb right Ion chamber, showing drift of ions. Incident radiation is the dotted line. An ionization chamber is an instrument constructed to measure the number of ion s within a medium which we will consider to be gaseous, but can also be solid or liquid . It usually consists of a gas filled enclosure between two conducting electrodes the anode and cathode . The electrodes may be in the form of parallel plates Parallel Plate Ionization Chambers PPIC , or coaxial cylinders to form a convenient portable detector in some cases one of the electrodes may be the wall of the vessel itself. When gas between the electrodes is ionized by any means, such as by alpha particle s, beta particle s, X ray s, or other radioactive emission, the ions and dissociated electrons move to the electrodes of the opposite Chemical polarity polarity , thus creating an ionization current which may be measured by a galvanometer or electrometer . Each ion essentially deposits or removes a small electric charge to or from an electrode, such that the accumulated charge is proportional to the number of like charged ions. A voltage ... having a frequency related to the incident radiation. Applications Nuclear industry Ionization chambers ..., and when they collide with gas in the ionization chamber mostly nitrogen and oxygen the momentum ... and radiotherapy , ionization chambers are used to ensure that the dose delivered from a therapy unit ... . Ionization chambers are connected to electrometers, and they typically report a collected charge in Coulomb ... more details
Image NanoESIFT.jpg right thumb Electrospray nanoSpray ionization source Electrospray ionization ESI .... The development of electrospray ionization for the analysis of biological macromolecules ref cite journal author Fenn, J. B. Mann, M. Meng, C. K. Wong, S. F. Whitehouse, C. M. title Electrospray ionization ... Foundation in Philadelphia, Pennsylvania. Mass spectrometry using ESI is called electrospray ionization ... Fenn ESI Instrument.jpg thumb Fenn s first electrospray ionization source top coupled to a single ... Geoffrey Ingram Taylor Ionization mechanism The liquid containing the analyte s of interest is Electrospray ... extensive solvent evaporation, the typical solvents for electrospray ionization are prepared by mixing ... other ionization sources. The analytes are sometimes involved in Electrospray Closing the electrical ... ensure improved ionization efficiency. In 1994, two research groups coined the name micro electrospray ... unfolding of proteins monitored by electrospray ionization mass spectrometry Distinguishing two state ... Electrospray Ionization ref ref Cite author Sobott Robinson year 2004 journal International Journal ... ionization is the ion source of choice to couple High performance liquid chromatography liquid chromatography ... has been studied. Noncovalent gas phase interactions Electrospray ionization is also ideal in studying ... Electrospray Protein mass spectrometry Taylor cone Desorption electrospray ionization Sonic spray ionization References Reflist Bibliography refbegin cite book author Cole, Richard title Electrospray ionization mass spectrometry fundamentals, instrumentation, and applications publisher Wiley location ... Biochemical and biotechnological applications of electrospray ionization mass spectrometry publisher ... External links http www.magnet.fsu.edu education tutorials tools ionization esi.html Electrospray Ionization Primer National High Magnetic Field Laboratory MeshName Electrospray Ionization Mass Spectrometry ... DEFAULTSORT Electrospray Ionization Category Ion source ar de Elektrospray ... more details
Charge exchange ionization also known as charge transfer ionization is a gas phase reaction between an ion and an atom or molecule in which the charge of the ion is transferred to the neutral species. ref GoldBookRef title charge exchange ionization file C00989 ref For example math A B to A B math . See also Associative ionization Chemi ionization Penning ionization References Reflist refbegin refend atomic physics stub Category Ion source it Ionizzazione per scambio di carica simmetrico ... more details
Infobox chemical analysis name Probe Electrospray Ionization PESI image File PESI.png thumb caption Conceptual diagram of the PESI ion source acronym PESI classification Mass spectrometry analytes Organic molecule s br Biomolecule s related Electrospray ionization hyphenated Probe electrospray ionization PESI is a modified version of conventional electrospray ionization ESI , where the capillary for sample solution transferring is replaced by a solid needle with a sharp tip. PESI was first introduced by Kenzo Hiraoka et al. in 2007 ref cite journal author Hiraoka K. Nishidate K. Mori K. Asakawa D. Suzuki S. title Development of probe electrospray using a solid needle journal Rapid Communications in Mass Spectrometry year 2007 volume 21 pages 3139 3144 doi 10.1002 rcm.3201 pmid 17708527 ref . Compared with conventional electrospray ionization , high salt tolerance and direct sampling and low sample consumption can be found with PESI. Of course, PESI is not a continuous process at all. Normally, the needle for sampling and spraying can be driven up and down under a frequency of 3 5 Hz. References Reflist Mass spectrometry DEFAULTSORT Probe Electrospray Ionization Category Ion source Category Mass spectrometry ... more details
Electron capture ionization is the ionization of a gas phase atom or molecule by attachment of an electron to create an ion of the form A sup sup . The reaction is math A e overset M to A math where the M over the arrow denotes that to conserve energy and momentum a third body is required the molecularity of the reaction is three . Electron capture can be used in conjunction with chemical ionization . ref Citation doi 10.1021 ac50035a017 title Electron capture negative ion chemical ionization mass spectrometry year 1978 author Donald F. Hunt Frank W. Crow journal Analytical Chemistry volume 50 issue 13 pages 1781 ref An electron capture detector is used in some gas chromatography systems. ref GoldBookRef title electron capture detector in gas chromatography file E01981 ref See also Electron capture dissociation References Reflist analytical chem stub Category Ion source ... more details
Summary An SVG version of Image Impact ionization schematic.gif . Author User Jaraalbe Jaraalbe 15 15, 3 December 2005 UTC Edited by User Timichio Timichio User talk Timichio talk 17 59, 11 May 2008 UTC Schematic of impact ionization, showing an energetic electron losing energy and creating an electron hole pair. Licensing GFDL migration relicense ... more details
Infobox chemical analysis name Atmospheric pressure chemical ionization image Apci.gif caption Atmospheric pressure chemical ionization interface acronym APCI classification Mass spectrometry analytes Organic molecule s br Biomolecule s related Chemical ionization br Electrospray hyphenated Liquid chromatography mass spectrometry Atmospheric pressure chemical ionization APCI is an Ion source ionization method used in mass spectrometry . It is a form of chemical ionization which takes place at atmospheric pressure. ref name pmid17405144 cite journal author Prakash C, Shaffer CL, Nedderman A title Analytical strategies for identifying drug metabolites journal Mass spectrometry reviews volume 26 issue 3 pages 340 69 year 2007 pmid 17405144 doi 10.1002 mas.20128 ref How it works APCI allows for the high flow rates typical of standard bore High performance liquid chromatography HPLC to be used directly, often without diverting the larger fraction of volume to waste. Typically the mobile phase containing eluting analyte is heated to relatively high temperatures above 400 degrees Celsius , sprayed with high flow rates of nitrogen and the entire aerosol cloud is subjected to a corona discharge that creates ion s. Often APCI can be performed in a modified electrospray ionisation ESI source. The ionization occurs in the gas phase, unlike ESI, where the ionization occurs in the liquid phase. A potential advantage of APCI is that it is possible to use a nonpolar solvent as a mobile phase solution, instead of a polar solvent, because the solvent and molecules of interest are converted to a gaseous state before reaching the corona discharge pin. Typically, APCI is a less soft ionization technique than ESI, i.e. it generates more fragment ions relative to the parent ion. ref name pmid16723751 cite journal author Zaikin VG, Halket JM title Derivatization in mass spectrometry 8. Soft ionization mass spectrometry of small molecules journal European journal of mass spectrometry Chichester ... more details
unreferenced date August 2009 In particle physics , gaseous ionization detectors are detectors designed to seek the presence of particles a particle detector . If a particle has enough energy to ion ize a gas atom or molecule, the resulting electron s and ion s cause a current flow which can be measured in different ways. The three basic types of gaseous ionization detectors are br ionization chamber s proportional counter s Geiger M ller tube s All of these have the same basic design of two electrode s separated by air or a special counting gas, but each uses a unique method to form the total number of ion pairs that are collected. ref McGregor, Douglas S. Chapter 8 Detection and Measurement of Radiation. Fundamentals of Nuclear Science and Engineering, Second Edition. By Kenneth J. Shultis and Richard E. Faw. 2nd ed. CRC, 2007. 202 222. Print. ref The strength of the electric field between the electrodes determines the detector s response to ionizing radiation . Ionization chamber s operate at a low voltage, selected such that no avalanche multiplication takes place. Current is generated by the drift of ions to anode or cathode. Proportional counter s operate at a slightly higher voltage, selected such that limited avalanche multiplication takes place. The avalanche is localised, rather than spreading widely through the detecting gas, so that an output current pulse is generated which is proportional to the detected particle energy. The term gas proportional detector GPD is generally used in radiometric practice, and the property of being able to detect particle energy is particular ... Mueller counter. Wire chamber s are essentially gaseous ionization detectors with many electrodes instead of one. Ionization type smoke detector s are gaseous ionization detectors. A bit of radioactive ... the plates where the ionization is taking place, the ionized gas can be neutralized leading to a reduced ... Ionization Detectors Category Particle detectors de Straw Detektor it Rivelatore a gas lt Dujinis ... more details
Unreferenced stub auto yes date December 2009 A discharge ionization detector DID is a type of detector used in gas chromatograph y. Principle A DID is an GC ion detector ion detector which uses a high voltage electric discharge to produce ion s. The spark ionizes helium atoms that are mixed with components as they elute from the gas chromatograph GC s column, causing the components to become ionized. The ion s produce an electric current , which is the signal information theory signal output of the detector. The greater the concentration of the component, the more ions are produced, and the greater the current. Application DIDs are sensitive to a broad range of components. DIDs are non destructive detectors. They do not destroy consume the components they detect. Therefore they can be used before other detectors in multiple detector configurations. DIDs are an improvement over Helium ionization detector s in that they contain no radioactive source.Figure should be included. DEFAULTSORT Discharge Ionization Detector Category Gas chromatography Analytical chemistry stub ... more details
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