ISSN:
0030-493X
Schlagwort(e):
Chemistry
;
Analytical Chemistry and Spectroscopy
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Desorption chemical ionization mass spectrometry employing ammonia as the reagent gas has been extensively used to obtain molecular mass and structural information on a wide variety of compounds. Mass-deficient reference standards normally used for calibration purposes in mass spectrometry do not provide adequate mass spectra under ammonia chemical ionization conditions. In order to overcome this problem a mixture of ammonia and methane as reagent gases was employed. In high-resolution accurate mass measurement experiments, this gas mixture allows the simultaneous detection of mass spectra of perfluorokerosene adequate for calibration purposes and spectra containing molecular mass information of the analyte. A needle valve system was used to control the composition of the gas mixture introduced into the ion source. For positive-ion accurate mass measurements of higher masses (up to m/z = 2300), Fomblin 18/8 oil was successfully used as a reference standard under ammonia, methane and isobutane desorption chemical ionization conditions.
Zusätzliches Material:
8 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/oms.1210290808
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