Review Secondary ion mass spectrometry in geochemistry and cosmochemistry: determination and distribution of carbon and hydrogen in silicate samples
T14N1
S.N. Shilobreeva
Based on a review of recent domestic and international literature, examples of the use of secondary ion mass spectrometry (SIMS) for the analysis of carbon and hydrogen in the solution of particular problems in geochemistry and space chemistry were presented. Particular attention was paid to problems that arise during calibration procedure for quantitative determination of carbon and hydrogen by SIMS. A summary was given of the current equipment that is used for SIMS analysis. Mass spectral imaging method based on a mathematic processing of the recorded carbon and hydrogen secondary ion currents for visualization of 3D distribution of the elements was considered in details.
T14N1
Содержание
Optimization of material analysis conditions for laser-assisted atom probe tomography characterization
T14N1
O.A. Raznitsyn, A.A. Lukyanchuk, A.S. Shutov, S.V. Rogozhkin, A.A. Aleev
Atom-probe tomography (APT) analysis with a femtosecond laser is one of the most promising techniques to characterize local variation of chemical distribution in materials on a sub-nanometer spatial resolution. In this study, the influence of APT analysis conditions on the accuracy of data recovery for chromium steels and alloys was investigated. Dependences of the mass resolving power and the detected composition of chromium as a function of laser power, the specimen geometry and the evaporation rate are presented.
New approaches to the application of DART mass spectrometry coupled with planar chromatography for analysis of mixtures of organic compounds
T14N1
M.V. Ovcharov, S.S. Barsegyan, S.A. Kovaleva, L.N. Kulikova, R.S. Borisov
A desorption cell for TLC/DART mass spectrometry is developed. Analysis of mixtures of pharmaceutical substances has shown that the proposed approach can improve the sensitivity of the method and achieve the reproducibility of recorded mass spectra and selected ions chromatograms.
Possibilities for eneregy transport into radio-frequency quadrupole by shifted supersonic gas jet. II. Accumulation and heating of ions
T14N1
V.V. Raznikov, V.V. Zelenov, E.V. Aparina
The aim of this work is establishment of ability of the supersonic jet to accumulate the dense enough ion clouds inside the quadrupole, the ion cloud being “heated” up to relatively high temperature under relatively low density of residual gas (at pressure less than 10–4 Torr). Kinetic measurements gave estimated number of accumulated ions at the beginning of the quadrupole of about 2•107 and their internal temperature of 6000 K.
Study of the products of alkaline decomposition of hydrolysis lignin by high resolution mass spectrometry with atmospheric pressure photoionization
T14N1
D.S. Kosyakov, E.V. Ipatova, S.M. Krutov, N.V. Ul’yanovskii, I.I. Pikovskoi
A method of high resolution mass spectrometry with acetone doped atmospheric pressure photoionization was used to study the products of alkaline solvolysis of hydrolysis lignin. It was found that the mass spectrum of hydrolysis lignin depolymerization products comprises about seven thousand peaks of oligomers containing up to 10 aromatic units with an average molecular weight of 150 Da. The calculation of the elemental compositions of all detectable oligomers and their visualization in van Krevelen coordinates allowed us to show that the studied sample is different from the native (virgin released) lignin due to the presence of fractions with a high oxygen content and highly unsaturated condensed structures, including polyaromatic hydrocarbons. To characterize the structural units of lignin oligomers an approach based on the collision induced dissociation of precursor ions in a broad m/z range was used.