ISSN:
0306-042X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Methyloxime trimethylsilyl ether derivatives are frequently employed in gas chromatographic and mass spectrometric analysis of steroids. Under certain instrumental conditions, unusual mass spectra were recorded from some corticosteroid methyloxime trimethylsilyl ether derivatives, reflecting degradation by contact of the steroids with active surfaces in the gas chromatograph mass spectrometer interface. This occurred prior to electron impact ionization. Fragmentations of the degradation products of methyloxime trimethylsilyl ether derivatives of tetrahydrocortisol and tetrahydrodeoxycorticosterone are described, as representatives of C21 steroids with dihydroxyacetone and α-ketol side chains. Elemental compositions of ions were confirmed by high resolution mass spectrometric analysis. Derivatives of steroids with glycerol side chains, e.g. cortolone, showed no evidence of degradation. The problem was overcome by ensuring inertness of the glass restrictor interface and by preventing, as far as posssible, contact of sample with metal surfaces in the source housing.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200091202
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