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Determination of the synthetic steroid norgestomet in bovine plasma by capillary column gas chromatography/negative chemical ionization mass spectrometry
Author(s) -
Kaykaty Maurice,
Chang Tsailing,
Weiss George
Publication year - 1988
Publication title -
biomedical and environmental mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0887-6134
DOI - 10.1002/bms.1200170208
Subject(s) - chemistry , chromatography , chemical ionization , mass spectrometry , oxime , gas chromatography , acetonitrile , analytical chemistry (journal) , gas chromatography–mass spectrometry , detection limit , ethyl acetate , ion , ionization , organic chemistry
A sensitive and specific method is described for the determination of norgestomet in bovine plasma as low as 10 ppt with better than 83% average recovery and a relative standard deviation (RSD) of range 1–3%. Norgestomet is separated from the bulk of the endogenous substances in plasma by adsorption on a PrepSep C 18 extraction column and elution with acetonitrile. The residue after evaporation of acetonitrile is reacted with O ‐(2,3,4,5,6‐pentafluorobenzyl)hydroxylamine hydrochloride to form syn and anti geometric isomers of the mono‐oxime derivative. The derivative, after further clean‐up and evaporation of solvent, is reconstituted with cyclohexane, and an aliquot is analyzed by capillary column gas chromatography/negative chemical ionization mass spectrometry using methane as the carrier gas. Selected ion monitoring was employed to detect the [M – HF] − fragment ion of the norgestomet mono‐oxime derivative ( m/z 547) and its dideuterated mono‐oxime analog ( m/z 549) which serves as the internal standard. Quantification is achieved by using the Quantitative Selectd Ion Monitoring Processing System (QSIMPS) softwere to generate a standard curve of fragment ion area ratios v. concentration of norgestomet, and then calculate sample concentrations.