Carbon nano coatings: new approach to obtaining mass spectra of low molecular compounds using surface assisted laser desorption/ionization mass spectrometr
T12N3
D.S. Kosyakov, E.A. Sorokina, N.V. Ul’yanovskii, E.A. Varakin,
D.G. Chukhchin, N.S. Gorbova
A simple and rapid way to obtain the targets for investigation of low molecular weight compounds by surface-assisted laser desorption / ionization mass spectrometry (SALDI), comprising a vacuum sputtering of the carbon layer with thickness of about 50 nm onto the metal surface, is proposed. The resulting coatings are characterized by homogenity, hydrophobicity and a high mechanical strength, eliminating the possibility of contamination of the mass spectrometer. The comparison of the SALDI mass spectra of test compounds recorded with the aid of conventional carbon materials and carbon nanocoating demonstrates such advantages of the latter as high spectral resolution and the absence of spectral interferences in the low values of m/z.
Масс-спектрометрические исследования химического состава образцов окружающей среды Эльконского урановорудного района
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Optimization of sample preparation conditions in the study of lignin by MALDI mass spectrometry method
T11N2
D.S. Kosyakov, N.V. Ul’yanovskii, E.A. Sorokina, N.S. Gorbova
In the present study the comparison of efficacy of six crystalline matrices, as well as their mixtures for MALDI of lignin is done, the effect of sample application technique and matrix/analyte ratio on the quality of the mass spectra is studied. It is established that the best results can be obtained when α-cyano-4-hydroxycinnamic and 2,5-dihydroxybenzoic acids, a well as 2,4,6-trihydroxyacetophenone are used as matrices, taken in 10–100-fold excess with respect to lignin and sequentially applied to the target in order «analyte–matrix– analyte». It is proposed for the first time to use ionic liquids as martices for obtaining of lignin MALDI mass spectra. It is shown that the ionic liquid N-tert-butyl-N-isopropyl-N-methylammonium α-cyano-4-hydroxycinnamate, forming a homogeneous solution with lignin gives substantially better results when compared with crystalline matrices in terms of intensity of the obtained mass spectra, and reproducibility. The structure of the MALDI mass spectra of dioxane lignin of fir caused by the predominance in the macromolecule units derived from α-guaiacylpropanone is analyzed.
Определение редкоземельных элементов в геологических объектах
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