Wyniki wyszukiwania - BazTech

1

Połączenie chromatografu cieczowego ze spektrometrem mas - stare i nowe rozwiązania

Kot-Wasik A., Jakimska A., Wasik A., Namieśnik J.

Analityka : nauka i praktyka

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2012

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nr 2

4-14

PL

Współczesna analityka ma do dyspozycji bardzo rozległy asortyment narzędzi analitycznych, wśród których chromatografia cieczowa ma swoje niepodważalne miejsce. Dzięki połączeniu z MS możliwe jest prowadzenie badań próbek w celu oznaczenia składników, które występują na poziomie śladów, a nawet ultraśladów.

2

Structure Analysis on Complexes of XanthoneGlycosides and Metal Ions Using Electrospray Ionization Tandem Mass Spectrometry

Sun J. G., Zhang Y., Wang L., Xue X. Y., Xiao H. B., Liang X. M.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 10

1687-1700

EN

The structure and fragmentation mechanism of metal (Mn(II), Al(III) and Cu(II)) complexes of xanthone glycosides as well as metal coordination sites were investigated by electrospray ionization tandem mass spectrometry. Four Mn(II) complexes of xanthone glycoside with different stoichiometric ratios were observed from swertianin 7-Orhamnosyl( 1 rarr 2)xyloside, swertianin 7-O-xylosyl(1 rarr 2)xyloside and swertianolin, while only two complexes were formed for 3,7,8-trimethoxy-1-O-primeverosyloxanthone, 2,3,5-trimethoxy-1-O-primeverosyloxanthone and 2,3,4,5-tetramethoxy-1-Oprimeverosyloxanthone, respectively. For xanthone glycoside-Cu(II) complexes, three complexes with different stoichiometric ratios were observed from swertianin 7-Orhamnosyl( 1 rarr 2)xyloside, swertianin 7-O-xylosyl(1 rarr 2) xyloside and swertianolin, but only one Al(III) complexes were formed for above three xanthone glycosides. Based on the analysis of metal complexes by tandem mass spectrometry, a fragmentation mechanism for 1:1 swertianin 7-O-rhamnosyl(1rarr 2)xyloside-Mn(II) complex was proposed and the structures of four swertianin 7-O-rhamnosyl(1 rarr 2)xyloside-Mn(II) complexes were interpreted. In addition, the hydroxyl groups in the oligosaccharide chains, the hydroxyl groups substituted at C-1 and C-8, and the carbonyl group in the C-ring of the aglycone, were proved to be the dominant coordination sites in the xanthone glycosidemetal complexes.

3

Studies on the Complexation of Alkali Metal Cations by Macrocyclic Diamides Using Electrospray Ionization Mass Spectrometry (ESI-MS)

Tarnowski P., Danikiewicz W., Jurczak J.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 7

927-935

EN

Several macrocyclic diamides have been tested as ligands for complexation of alkali metal cations. Electrospray ionization mass spectrometry was found to be a perfect tool for investigation of host-guest interaction between ligands and cations studied. Effect of the ring size and regioisomerism of the amido groups on complexation properties of ligands were also investigated.

4

Fragmentation and Skeletal Rearrangements of the Protonated Spiro(2H-benzimidazole-2-4'-pyrazole)-5'-one Dyes Studied by Electrospray Ionization and Liqiud Secondary Iohn Mass Spectrometry

Frański R., Kozik T., Schroeder G., Kucybała Z., Pączkowski J.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 10

1301-1312

EN

The mass spectrometric decomposition of the titled compounds was studied by using electrospray ionization (ESI) and liquid secondary ion mass spectrometry (LSIMS) as a methods for [M+H]+ ions generation. Low-energy collision induced dissociation (fragmentation "in source") mass spectra for ESI and B/E linked scan mass spectra of metastable ions for LSIMS were performed. In order to better understand the decomposition of the compounds studied, the mass spectra of isotopically labelled compounds were recorded. The fragmentation pathways of [M+H]+ ions were found to be complex and skeletal rearrangements were observed. It was deduced that subsequent loss of NH3 and H2O molecules leads to the formation of ions with polycyclic structures. The fragment ion [133]+ and its complementary fragment ion [M+H-132]+ can be considered as protonated molecules of 3-methyl-1H-indazole and 2-hydroxyquinoxaline, respectively. Loss of the CH3CN molecule also occurs and this is rather simply process. Aniline elimination (H2N-C6H5) and formation of ions at m/z 146 are complex processes and it was difficult