摘要:

AbstractIsomeric glycoconjugates have been distinguished using desorption negative‐ion chemical ionization/tandem mass spectrometry (DNCI–MS/MS). The structure of the leaving terpene influences the orientation of consecutive decompositions during collisionally activated decomposition (CAD) of [M–H]−ions which pass through a glucose alkoxide intermediate ion. This apparent „memory effect”︁ can be rationalized by considering the production of anion‐induced d

ISSN:0951-4198    

DOI:10.1002/rcm.1290030302

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractA new hybrid mass spectrometer of BEQiQu geometry (B, magnetic sector; E, Electric sector; Qi, quistor; Qu, quadrupole mass filter) is described. The high resolution stage (BE) is coupled to a quistor via a series of deceleration lenses, and this is followed by a mass‐analysing quadrupole. This configuration enables the storing of ions, investigation of their gas‐phase chemistry and the subsequent identification of the resulting fragment or product i

ISSN:0951-4198    

DOI:10.1002/rcm.1290030303

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractAluminium‐clad fused silica capillary columns can be used with magnetic sector mass spectrometers. The column end needs to be pulled back a millimetre or so from the ion source to avoid electrical arcing. The chromatographic integrity is maintained. This brings the benefits of robust construction and high temperature gas chromatography/mass spectrometry to sector mass spectrometer

ISSN:0951-4198    

DOI:10.1002/rcm.1290030304

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractProduct ion spectra derived from molecule ions as the precursor ions for 14 alkylbenzenes have been studied under electron ionization and methane chemical ionization. The data have provided a satisfactory screening method for both detection and confirmation of such compounds at low parts per million levels.

ISSN:0951-4198    

DOI:10.1002/rcm.1290030305

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractTwo conjugated metabolites of methapyrilene hydrochloride isolated from mouse‐hepatocytes were examined by mass spectrometry using fast‐atom bombardment (FAB) and thermospray ionization. The major metabolite, methapyrilene glucuronide, was identified based on a prominent peak due to the protonated molecule as well as the loss of the dimethylamine and sugar moieties. Identification of the second metabolite was complicated by large signals associated with the biological sample matrix. The complementary nature of the fragmentation observed in the mass spectra using FAB and thermospray ionization allowed this metabolite to be identified as the desmethylmethapyrilene glucuronide. The fragmentation observed using FAB ionization was not greatly affected by the presence of the glucuronide moiety. While loss of the sugar moiety indicated a glucuronide, additional fragmentation confirmed the presence of the underlying ethylenediamine substructure which is characteristic of this class of antihistami

ISSN:0951-4198    

DOI:10.1002/rcm.1290030306

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractPhosphohydroxylysine a compound found in the urine of two patients with a possible inborn error of hydroxylysine metabolism, and related phosphohydroxycompounds were investigated with fast‐atom bombardment tandem mass spectrometry techniques. This resulted in a reliable and quick identification method for phospho amino acids in genera

ISSN:0951-4198    

DOI:10.1002/rcm.1290030307

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractCapabilities of high resolution chromatography/tandem mass spectrometry for quantitation of polychlorinated dibenzo‐p‐dioxins and polychlorinated dibenzo furans have been investigated with a hybrid instrument. Selected‐transition monitoring procedures, collision energy and collision gases have been optimized for maximum sensitivity. The results are compared with those obtained by high resolution chromatography/high resolution mass spectro

ISSN:0951-4198    

DOI:10.1002/rcm.1290030308

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractProton‐bound dimers [ROH…\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm H}\limits^ + $\end{document}… HOR] have been studied under chemical ionization conditions. The structures of the fragment ions and the behaviour of variously deuterated ions when R = iC3H7lead to a proposed fragmentation pa

ISSN:0951-4198    

DOI:10.1002/rcm.1290030309

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

摘要:

AbstractAn on‐line coaxial continuous‐flow capillary‐zone electrophoresis/fast‐atom bombardment mass spectrometry (CZE/FAB‐MS) interface is described. This interface is shown to be capable of acquiring mass spectra in an online fashion from low femtomole amounts of peptides while maintaining high (hundreds of thousands of plates) electrophoretic separation efficiencies. Active electrophoretic transport of the analytes directly to the FAB probe tip obviates the need for a transfer line from the end of the CZE capillary to this point, and thereby precludes the zone broadening that would otherwise occur both within such a transfer line and in the connections between the CZE column and the transfer line. The capability of acquiring an on‐line tandem mass spectrometry (MS/MS) spectrum of an electrophoretically separated analyte using this interface is also d

ISSN:0951-4198    

DOI:10.1002/rcm.1290030310

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY

ISSN:0951-4198    

DOI:10.1002/rcm.1290030313

出版商:Heyden&Son Limited    

年代:1989

数据来源: WILEY