Search results for "Ionization mass"
showing 10 items of 29 documents
Use of thermal ionization isotope dilution mass spectrometry (TI-IDMS) as an oligo-element method for the determination of photographically relevant …
1998
Thermal ionization isotope dilution mass spectrometry (TI-IDMS) was used as an oligo-element method for the determination of Cr, Cd and Pb in photographic AgCl emulsions. After addition of an appropriate amount of isotopically enriched spikes (53Cr, 116Cd and 206Pb) to the solid samples, the latter were completely dissolved in NH3 solution, permitting isotopic exchange to take place. Thereafter, AgCl was selectively removed by precipitation, whereby ultrasonic treatment was used to enhance the recovery of the elements of interest. Despite the use of concentrated HNO3 and H2O2 during further sample processing, preliminary experiments indicated the presence of a substantial remainder of the o…
Identification of ground water contaminations by landfills using precise boron isotope ratio measurements with negative thermal ionization mass spect…
1997
Precise boron isotope ratio measurements with negative thermal ionization mass spectrometry were used for the identification of ground water contaminations by leakages of landfills. BO 2 - thermal ions were produced to determine the 11 B/ 10 B isotope ratio, which was expressed as δ 11 B value in ‰ normalized to the standard reference material NIST SRM 951. For example, household waste influences the boron isotope ratio by specific components such as washing powder. In the case of one investigated landfill low δ 11 B values correlate well with high boron concentrations in contaminated seepage water samples and vice versa for uncontaminated ground water samples. Possible boron contributions …
Determination of trace elements by resonant ionization mass spectrometry (RIMS)
1988
A resonant ionization mass spectrometer has been developed as an analytical tool for the detection of trace elements, especially of plutonium and other radionuclides. The sample, deposited on a rhenium filament, is evaporated by electrical heating and the atoms of the element under investigation are selectively ionized by laser light delivered from three dye lasers pumped by a copper vapour laser. The resulting photoions are detected in a time-of-flight spectrometer with a channelplate detector. For plutonium a mass resolution of M/δM=1500 was obtained and an overall detection efficiency of 4×10−6 was determined for stepwise excitation and ionization via autoionizing states. With a laser li…
Resonance Ionization Mass Spectroscopy for Trace Analysis
1990
My first lecture at this Summer School on Applied Laser Spectroscopy dealt with the determination of nuclear ground-state properties, i.e. atomic mass M, the nuclear spin I, the magnetic dipole moment μ I, the spectroscopic quadrupole moment Q, and the changes in the mean-square charge radius δ(r2) A,A´ between isotopes with mass number A and A´. These quantities can be determined for stable, long-, or short-lived isotopes by mass spectrometry and optical spectroscopy. In the latter case, the hyperfine structure (HFS) and the volume effect of the isotope shift (IS) are determined in atomic levels or optical transitions. The state of the art mainly concerning short-lived nuclei is described …
Trace detection of radiotoxic isotopes by resonance ionization mass spectrometry
1995
Resonance ionization spectroscopy combined with mass spectrometry (RIMS) has become an important technique for ultratrace environmental analysis, and is particularly well suited for the detection of long-lived radio-toxic isotopes. A variety of experimental approaches have been developed to address the specific requirements posed by individual isotopes, which have widely differing physical, chemical, and environmental properties. In this paper we discuss the principles and recent progress in the development of three different methods that are being used for the analysis of radiotoxic species. These include measurement of actinides using triple-resonance ionization and time-of-flight mass sp…
Effect of protonation and deprotonation on the gas phase reactivity of fluorinated 1,2,4-triazines
2008
Positive and negative electrospray mass spectrometry (MS), in-time and in-space MS n experiments, high-resolution and accurate mass measurements obtained with an Orbitrap, together with density functional theory calculations have been used to study the gas-phase ion chemistry of a series of fluorinated 1,2,4-triazines. As a result of low-energy collision-induced dissociations, occurring in an ion trap and in a triple quadrupole, their protonated and deprotonated molecules show interesting features depending on the nature and structure of the precursor ions. The occurrence of elimination/hydration reactions produced by positive ions in the ion trap is noteworthy. Decompositions of deprotonat…
Development of a sequential data correction method for isotope ratio analysis by resonance ionization mass spectrometry
2015
A sequential data correction method using several experimental parameters of pulsed resonance ionization mass spectrometry was developed to reduce mass discrimination effects for isotope ratio analysis as well as fluctuations in the ion count rate. This correction method was applied to isotope ratio determination of stable titanium isotopes using a two-step, single color ionization scheme. A significant improvement of the precision of the measured isotopic ratio of stable titanium isotopes was demonstrated after correction with a parameter set consisting of laser power, atmospheric pressure, and laser frequency.
Resonance ionization mass spectroscopy for nuclear research and trace analysis
1987
Resonance ionization mass spectroscopy (RIMS) has been applied, firstly, to a study of the nuclear properties of short-lived Au isotopes at the on-line isotope separator ISOLDE at CERN and, secondly, to a trace-analysis experiment of Pu.
Selective ultra trace isotope determination in environmental and biomedical studies by high-resolution resonance ionization mass spectrometry
2002
The precise determination of relative abundances of ultra trace isotopes in the range below 10 -9 is of importance for a wide spectrum of applications in fields like environmental protection, cosmo-chemistry, bio-medical tracer studies or geological and geo-chronological investigations. The necessary high isotopic selectivity, rather complete isobaric suppression and good overall efficiency for these investigations is provided by high-resolution resonance ionization mass spectrometry. Multi-step continuous wave laser excitation and ionization using diode lasers at a compact quadrupole mass spectrometer has been optimized to become a powerful and reliable experimental method, which is just b…
Mass spectrometry of atomic ions produced by in-trap decay of short-lived nuclides
2005
The triple-trap mass spectrometer ISOLTRAP at ISOLDE/CERN has demonstrated the feasibility of mass spectrometry of in-trap-decay product ions. This novel technique gives access to radionuclides, which are not produced directly at ISOL-type radioactive ion beam facilities. As a proof of principle, the in-trap decay of $^{37}K^+$ has been investigated in a Penning trap filled with helium buffer gas. The half-life of the mother nuclide was confirmed and the recoiling $^{37}Ar^+$ daughter ion was contained within the trap. The ions of either the mother or the daughter nuclide were transferred to a precision Penning trap, where their mass was determined.