Quantification of 5 alpha- and 5 beta-androstanediols in urine by gas chromatography-mass spectrometry.

1987 ◽  
Vol 33 (2) ◽  
pp. 256-260 ◽  
Author(s):  
L Muller ◽  
G Phillipou
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Diurnal Rhythm ◽  
Capillary Gas Chromatography ◽  
Internal Standard ◽  
Reference Intervals ◽  
Gas Chromatography Mass Spectrometry ◽  
Positive Bias ◽  
Men And Women ◽  
Chromatography Mass Spectrometry

Abstract We measured concentrations of 5 alpha-androstane-3 alpha,17 beta-diol (Ad) and 5 beta-androstane-3 alpha,17 beta-diol (beta-Ad) in urine by specific capillary gas chromatography-mass spectrometry, with [16,16,17 alpha-2H3]-5 alpha-androstane-3 alpha,17 beta-diol as the internal standard. Comparison of the so-derived reference intervals for Ad and beta-Ad in men and women with those previously published indicates a significant positive bias for many of the previous assays in comparison with our procedure. Both Ad and beta-Ad have a pronounced diurnal rhythm, with maximum excretion in the interval 2300-0700 hours. Concentrations of Ad and beta-Ad were significantly correlated (r = 0.786, p less than 0.001), but the ratio of Ad to beta-Ad was not correlated to that for androsterone to etiocholanolone, the major 5 alpha and 5 beta metabolites of androgens in urine.

Measurement of rimantadine in plasma by capillary gas chromatography/mass spectrometry with a deuterium-labeled internal standard.

1988 ◽  
Vol 34 (8) ◽  
pp. 1597-1599 ◽  
Author(s):  
D A Herold ◽  
P K Anonick ◽  
M Kinter ◽  
F G Hayden
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Influenza A ◽  
Internal Standard ◽  
Antiviral Agent ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Stable Isotope Dilution ◽  
Chromatography Mass Spectrometry

Abstract Rimantadine is a synthetic antiviral agent used in prophylaxis and in treating the early stages of uncomplicated influenza A illness. We describe a stable isotope-dilution assay involving capillary gas chromatography/mass spectrometry. We used 200 ng of d3-rimantadine, added to 1 mL of plasma, as the internal standard. The rimantadine was extracted from the plasma with a Bond-Elut CN column, the column was washed with water, and the rimantadine was eluted with methanol, dried, and treated to form the t-butyldimethylsilyl derivative. The mass spectrometer was operated in the selected ion monitoring mode. Ions at m/z 236 and m/z 239 were monitored, corresponding to the loss of C4H9 from the rimantadine derivative and d3-rimantadine, respectively. Within-run precision (CVs) ranged from 8.9% at 29 micrograms/L to 3.2% at 1666 micrograms/L. Corresponding data for between-run precision were 5.4% and 1.7%. Treated volunteers (n = 86) provided plasma samples with a concentration range of 153 to 1127 micrograms/L. This simplified method allows rapid, precise assay of rimantadine in plasma.

Screening and quantification of hypnotic sedatives in serum by capillary gas chromatography with a nitrogen-phosphorus detector, and confirmation by capillary gas chromatography-mass spectrometry.

1986 ◽  
Vol 32 (2) ◽  
pp. 325-328 ◽  
Author(s):  
V A Soo ◽  
R J Bergert ◽  
D G Deutsch
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Detector Response ◽  
Capillary Gc ◽  
Chromatography Mass Spectrometry ◽  
Nitrogen Phosphorus Detector ◽  
Sedative Drugs ◽  
Nitrogen Phosphorus

Abstract We describe a quantitative screen for hypnotic-sedative drugs in which we use capillary gas chromatography with a nitrogen-phosphorus detector (GC/NPD) as the primary method and capillary gas chromatography-mass spectrometry (GC-MS) for confirmation. GC retention times of the acid-extracted underivatized drugs were stable (CVs less than 1%), and the detector response varied linearly over a 20-fold concentration range with a mean correlation coefficient for 11 drugs of 0.989. The limits of detection were satisfactory (0.5 mg/L in a 0.5-mL serum sample and 1-microL injection volume), as were precision (average CV 5.2% within day, 6.4% between day). The complementary use of capillary GC-MS not only unambiguously confirms presumptive peaks identified by GC, but also prevents reports of false positives and identifies compounds not included in the quantitative GC screen that may be listed in the GC-MS library.

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