The use of ion-molecule reactions with NH3 for selected reaction monitoring (SRM) in gas chromatographic/tandem mass spectrometric analysis is demonstrated for 2-methoxyethanol and chlorobenzene in methanol and urine. In the former, the reaction [CH3OC2H4]+ + NH3----[H2NC2H4]+ + CH3OH was followed;
Analyses of steroids in saliva using highly selective mass spectrometric techniques
β Scribed by Simon J. Gaskell; Elizabeth M. H. Finlay; Adrian W. Pike
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- English
- Weight
- 463 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1076-5174
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β¦ Synopsis
Highly selective techniques of gas chromatography mass spectrometry have been used in the unequivocal identification of salivary steroids at concentrations ranging from 20 pg ml-' to 20 ng m1-l. Oestradiol-l7P, for example, has been identified in pregnancy saliva by gas chromatography high resolution mass spectrometry selected ion monitoring of the bis-TMS ether and by gas chromatography mass spectrometry metastable peak monitoring of the bis-tert-butyldimethylsilyl ether. Dehydroepiandrosterone sulphate has been identified in saliva, following enzymic hydrolysis, by gas chromatography high resolution mass spectrometry selected ion monitoring of the tert-butyldimethylsilyl ether and methyl oxime tert-butyldimethylsilyl ether. These initial analyszs have been designed to guide the development of routine immunoassay procedures which may subsequently be validated by comparison with reference gas chromatographic mass spectrometric methods.
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