APPI

APPI is suitable for the ionization of nonpolar analytes, in which the photoionization of molecule M leads to the formation of a radical cation M . If the ionization potentials (IPs) of all other matrix elements are greater than the photon energy, then the ionization process is specific for the analyte. However, in the APPI, different processes can very strongly influence the detection of M [Pg.7]

1) In the presence of solvent molecules and/or other existing components in large excess, ion-molecule reactions can proceed. [Pg.7]

2) VUV photons are efficiently absorbed from the gas phase matrix. [Pg.7]

for example, in the presence of acetonitrile (often used mobile phase in HPLC), mainly [M 4- H ] is formed even though the IP of acetonitrile is more than 2.2 eV higher as the photon energy [64]. In general, in the case of polar compounds, which are dissolved in CH3CN/H2O, the formation of [M + H] is usually observed, while nonpolar compounds such as naphthalene usually form M [65]. [Pg.7]

A detailed mechanism for the formation of [M -I- H] was proposed by Klee et al. [66]. In APPI, the ion yield is reduced due to the limited VUV photon flux, and the interactions with solvent molecules. Therefore, the DA-APPI was introduced as a new ionization method from Bruins and employees [65]. [Pg.7]

Marrian C R K, Perkins F K, Brandow S L, Koloski T S, Dobisz E A and Calvert J M 1994 Low voltage electron beam lithography in self-assembled ultrathin films with the scanning tunneling microscope Appi. Rhys. Lett. 64 390... [Pg.319]

Shen Y R 1994 Nonlinear optical studies of surfaces Appi. Rhys. A 59 541... [Pg.319]

Muschlitz E E 1957 Formation of negative ions in gases by secondary collision processes J. Appi. Rhys. 28 1414-18... [Pg.821]

Page J B 1991 Many-body problem to the theory of resonance Raman scattering by vibronic systems Top. Appi. Phys. 116 17-72... [Pg.1227]

Oudar J-L, Smith R W and Shen Y R 1979 Polarization-sensitive coherent anti-Stokes Raman spectroscopy Appi. Rhys. Lett. 34 758-60... [Pg.1229]

Schaertel S A, Albrecht A C, Lau A and Kummrow A 1994 Interferometric coherent Raman spectroscopy with incoherent light some applications Appi. Rhys. B 59 377-87... [Pg.1229]

Kummrow A and Lau A 1996 Dynamics in condensed molecular systems studied by incoherent light Appi. Rhys. B 63 209-23... [Pg.1229]

Shanthi E, Dutta V, Baneqee A and Chopra K L 1980 Electrical and optical properties of undoped and antimony-doped tin oxide films J. Appi. Rhys. 51 6243-51... [Pg.1798]

Csepregi L, Kennedy E F, Gallagher T J, Mayer J W and Sigmon T W 1978 Substrate orientation dependence of the epitaxial regrowth rate from Si-implanted amorphous Si J. Appi. Phys. 49 3906... [Pg.1849]

Plieth W, Wilson G S and de la Fe C 1998 Spectroelectrochemistry a survey of in situ spectroscopic techniques Pure Appi. Chem. 70 1395... [Pg.1954]

Heydemann P L M 1997 The Bi l-ll transition pressure measured with a dead-weight piston gauge J. Appi. Phys. 38 2640... [Pg.1963]

Bridgman P W 1941 Explorations towards the limit of utilizable pressures J. Appi. Phys. 12 461... [Pg.1963]

Zhao Y, Barvosa-Carter W, Theiss S D, Mitha S, Aziz M J and Schiferl D 1998 Pressure measurement at high temperature using ten Sm YAG fluorescence peaks J. Appi. Phys. 84 4049... [Pg.1963]

Schmidt S C, Schiferl D, Zinn A S, Ragan D D and Moore D S 1991 Calibration of the nitrogen vibron pressure scale for use at high temperatures and pressures J. Appi. Phys. 69 2793... [Pg.1963]

Dura J A, Pippenger P M, Flalas N J, Xiong X Z, Chow P C and Moss S C 1993 Epitaxial integration of single crystal Cgq Appi. Rhys. Lett. 63 3443-5... [Pg.2427]

Fartash A 1994 Growth and microstructure of interfacially oriented large crystalline grain Cgq sheets Appi. Rhys. Lett. 64 1877-9... [Pg.2427]

Fischer J E, Werwa E and Fleiney P A 1993 Pseudo epitaxial Cgq films prepared by a hot wall method Appi. Rhys. A 56 193-6... [Pg.2427]

Gloge D 1971 Dispersion in weakly guiding fibers Appi. Opt. 10 2442... [Pg.2876]

Lau K T, Bar-Chaim N, Ury I and Yariv A 1983 Direct amplitude modulation of semiconductor GaAs lasers up to X-band frequencies Appi. Phys. Lett. 43 11... [Pg.2876]

Haller E E 1995 Isotopically engineered semiconductors Appl. Phys. Rev. J. Appi. Phys. 77 2857... [Pg.2897]

Micic O I ef a/1996 Highly efficient band-edge emission from InP quantum dots Appi. Phys. Lett. 68 3150... [Pg.2917]

Hashimoto H et ai 980 Direot observations of the arrangement of atoms around staoking faults and twins in gols orystals and the movement of atoms aooompanying their formation and disappearanoe Japan. J. Appi. Phys. 19 LI... [Pg.2920]

Klein D L ef a/1996 An approaoh to eleotrioal studies of single nanoorystals Appi. Phys. Lett. 68 2574... [Pg.2920]

Durston P J ef a/1997 Soanning tunnelling miorosoopy of ordered ooated oluster layers on graphite Appi. Phys. Lett. 71 2940... [Pg.2920]

Goldstein A N 1996 The melting of silicon nanocrystals submicrometre thin-film structures derived from nanocrystal precursors Appi. Phys. A 62 33... [Pg.2922]

Feil H, Dieleman J and Garrison B 1993 Chemical sputtering of Si related to roughness formation of a Cl-passivated Si surface J. Appi. Phys. 74 1303-9... [Pg.2942]

Barone M E and Graves D B 1995 Chemical and physical sputtering of fluorinated silicon J. Appi. Phys. 77 1263-74... [Pg.2942]

I h c simplest approximation to tlic Scfi rod in gcr equation is an in clepen dcri l-eleelron appi oxim alion, sucli as Ui e H iiekel method for tr-clcetron systems, developed by H. Huckel. I-atcr, others, principally Roald Hoffmann of Cornell University, extended tlie Htiekel approximations to arbitrary systems having both nand a electrons the Hxtended Huckel Theory (KHT) approximation. ... [Pg.219]

Ah initio calculation s can be performetl at th e Ilartree-Fock level of approximation, equivalent to a self-con sisten t-field (SCK) calculation. or at a post llartree-Fock level which includes the effects of correlation —defined to be everything that the Hartree-Fock level of appi oxiniation leaves out of a n on-relativistic solution to the Schrddinger ec nation (within the clamped-nuclei Born-Oppenh e-imer approximation ). [Pg.251]

International Union of Pure and AppHed Chemistry, Manual of Symbols and Terminologyfor Physicochemical Quantities and Units, Pergamon Press, Oxford, UK, 1919, Pure AppI Chem. 51, 1 (1979). [Pg.122]

Thei e ai e a few pi inciples of scale-up that can indicate which appi oach to take in eitliei case. Using geometi ic similai itv, the rnaci o-scale vai iables can be summai ized as follows ... [Pg.1624]

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