Determination of steroid hormones in a human-serum reference material by isotope dilution--mass spectrometry: A candidate definitive method for cortisol

Journal Article · Tue May 01 00:00:00 EDT 1984 · Clin. Chem. (Winston-Salem, N.C.); (United States)

OSTI ID:6880100

Patterson, D G; Patterson, M B; Culbreth, P H; Fast, D M; Holler, J S; Sampson, E J; Bayse, D D

We report a method, based on isotope dilution--mass spectrometry, for determining cortisol in a pooled specimen of human serum. Isotopically labeled cortisol is added to 5.0 mL of serum so that the molar concentrations of labeled cortisol and unlabeled cortisol are approximately equal. The specimen and two calibration standards are extracted with dichloromethane, and the extracted cortisol is converted to the methoxime-trimethylsilyl ether derivative. Samples and standards are analyzed by gas chromatography--mass spectrometry by monitoring the peak areas for m/z 605 and 608. The cortisol concentration is calculated by linear interpolation between the two bracketing standards. Variances of data collected during six weeks showed that the overall coefficient of variation (CV) was 0.69% (n . 32); the within-vial CV, 0.63%; the among-vial CV, 0.22%; and the among-day CV, 0.15% (means . 3.973 nmol/vial). Method specificity was demonstrated by liquid chromatographic as well as C/sub 8/ mini-column cleanup of samples before derivation, by alternative ion monitoring at m/z 636 and 639, and by negative-ion chemical ionization at m/z 459 and 462. Derivatives of all observed degradation products of cortisol under basic, neutral, and acidic conditions did not interfere.

• Research Organization: Centers for Disease Control, Department of Health and Human Services, Atlanta, GA
• OSTI ID: 6880100
• Journal Information: Clin. Chem. (Winston-Salem, N.C.); (United States), Journal Name: Clin. Chem. (Winston-Salem, N.C.); (United States) Vol. 30:5; ISSN CLCHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ANIMALS
BLOOD CHEMISTRY
BLOOD SERUM
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CHROMATOGRAPHY
CORTICOSTEROIDS
DERIVATIZATION
GAS CHROMATOGRAPHY
GLUCOCORTICOIDS
HORMONES
HYDROCORTISONE
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPE DILUTION
ISOTOPES
KETONES
LIQUID COLUMN CHROMATOGRAPHY
MAMMALS
MAN
MASS SPECTROSCOPY
ORGANIC COMPOUNDS
PREGNANES
PRIMATES
QUANTITATIVE CHEMICAL ANALYSIS
RADIOISOTOPES
SEPARATION PROCESSES
SPECTROSCOPY
STEROID HORMONES
STEROIDS
TRACER TECHNIQUES
VERTEBRATES