A semi-automatic control system has been developed for a spark-source mass-spectrometer, which permits close interaction between the operator, the instrument via electrical ion-detection and a computer via time-sharing (remote terminal) facilities.
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http://dx.doi.org/10.1016/0039-9140(72)80055-9 | DOI Listing |
Mass Spectrom (Tokyo)
December 2013
JEOL USA, Inc.
The introduction of DART and DESI sources approximately seven years ago led to the development of a new series of atmospheric pressure ion sources referred to as "ambient ionization" sources. These fall into two major categories: spray techniques like DESI or plasma techniques like DART. The selectivity of "direct ionization," meaning analysis without chromatography and with little or no sample preparation, depends on the mass spectrometer selectivity.
View Article and Find Full Text PDFJ Chem Phys
October 2012
Universidade de São Paulo, Instituto de Química, Departamento de Química Fundamental, Av. Prof. Lineu Prestes, 748, São Paulo, São Paulo, 05508-000, Brazil.
We present a detailed theoretical study of the stability of the gas-phase diatomic dications SnF(2+), SnCl(2+), and SnO(2+) using ab initio computer calculations. The ground states of SnF(2+), SnCl(2+), and SnO(2+) are thermodynamically stable, respectively, with dissociation energies of 0.45, 0.
View Article and Find Full Text PDFBiomed Mass Spectrom
September 1985
The main ionization methods in a mass spectrometer for isotope ratio determinations of the elements are discussed in this review. These methods are thermal ionization, spark source, electron impact, inductively coupled plasma and field desorption. As concerns thermal ionization, electron impact and field desorption, a survey of the possibilities of isotope analyses in the periodic table of the elements is given.
View Article and Find Full Text PDFTalanta
April 1979
Department of Chemistry, University of Antwerpen (U.I.A.), B-2610 Wilrijk, Belgium.
Sensitivity calibration has been performed for the spark-source mass-spectrometric analysis of iron, copper and aluminium matrices, with standard reference materials. The experimental relative sensitivity coefficients, corrected for discrimination effects in the mass spectrometer, are compared with values obtained with various empirical approaches to calculate relative sensitivity coefficients for an r.f.
View Article and Find Full Text PDFTalanta
July 1977
GTE Laboratories, Waltham, Massachusetts 02154, U.S.A.
A high pumping-speed vacuum system, incorporating a mechanical cryo-pump, was designed and built to attach to the source of a spark-source mass-spectrometer to reduce the partial pressure of carbon- and oxygen-containing gases. Pressures in the 10(-10) mmHg range were obtained, which provide a suitable environment for the determination of carbon and oxygen in tungsten. The effect of the partial pressure of CO on carbon and oxygen determination has been studied and characterized.
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