Using mono-, di-, tri-and tetrasaccharides, nucleosides, bile acids, riboflavin, gibberellin A3, aminoglycosides, flavanoid and cardenolide glycosides, the sodium salt of riboflavin phosphate and the quaternary ammonium drug propantheline bromide, the performance of a new moving belt interface for liquid chromatography mass spectrometry has been evaluated. It is shown to be superior to previous interfaces of this type in its ability to provide relative molecular mass information from thermally labile low volatility compounds. The spectra obtained are similar to those obtained by desorption chemical ionization.
A conventional bore liquid chromatograph has been interfaced to quadrupole and magnetic sector mass spectrometers configured for fast atom bombardment ionization via a continuous flow FAB probe. It is shown that post-column addition of FAB matrix and in-line ultraviolet detection facilities do not significantly compromise chromatographic integrity and that high quality mass spectra are obtainable from such FAB LC/MS studies.
EXPERIMENTALAll the experiments were performed on a Kratos MS-50 triple analyzer tandem mass spectrometer, of EBE geometry, which consists of a Nier-Johnson arrangement of an electric and a magnetic sector (MS-I), followed by an electric sector (MS-II)."'The parent ions were selected from the source by using the first two analyzers (EB); fragmentation occurred in the third field free region, and mass analysis of the resulting daughter ions was accomplished by scanning the final electric sector. The energy of the ionizing electrons was 70 eV, the accelerating voltage 8000 V, and the initial electric sector voltage 530 V. To avoid overlap of the [ml+l]' ions by [m,+H]' ions formed by ion/molecule reactions in the source, the sample pressure was kept as low as possible, and the ratio of [mi+ l]'/m? was remeasured several times during the experiments to ensure that it did not exceed the theoretical amount." The compounds were obtained from commercial sources and were used without additional purification.
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