Determination and Confirmation of cis-9-Tricosene in Technical Materials by Capillary Gas Chromatography and Gas Chromatography/Mass Spectrometry

1992 ◽  
Vol 75 (5) ◽  
pp. 878-882
Author(s):  
Jinren Ko ◽  
Jack Nguyen ◽  
Jim Burleson

Abstract A capillary gas chromatographic (GC) method was developed for the quantitation of cis-9-tricosene in technical material. This method is capable of resolving cis-9-tricosene from the trans-9-tricosene isomer and other impurities in technical 9-tricosene. Samples are dissolved in methylene chloride and analyzed by splitless GC using docosane as an internal standard. The integrity and purity of the peak of interest were confirmed by GC/mass spectrometry. The overall recovery of this method was 101.3 ± 0.82%. The correlation coefficient of the standard calibration curve was 0.9999. The system and method precision for cis-9-tricosene were 0.18 and 0.20%, respectively. The reproducibility of the method by different analysts was within 0.5%.

1987 ◽  
Vol 33 (2) ◽  
pp. 256-260 ◽  
Author(s):  
L Muller ◽  
G Phillipou

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.


1988 ◽  
Vol 34 (8) ◽  
pp. 1597-1599 ◽  
Author(s):  
D A Herold ◽  
P K Anonick ◽  
M Kinter ◽  
F G Hayden

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.


Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 207
Author(s):  
Kosuke Hata ◽  
Yuki Soma ◽  
Toshiyuki Yamashita ◽  
Masatomo Takahashi ◽  
Kuniyo Sugitate ◽  
...  

Calibration-Curve-Locking Databases (CCLDs) have been constructed for automatic compound search and semi-quantitative screening by gas chromatography/mass spectrometry (GC/MS) in several fields. CCLD felicitates the semi-quantification of target compounds without calibration curve preparation because it contains the retention time (RT), calibration curves, and electron ionization (EI) mass spectra, which are obtained under stable apparatus conditions. Despite its usefulness, there is no CCLD for metabolomics. Herein, we developed a novel CCLD and semi-quantification framework for GC/MS-based metabolomics. All analytes were subjected to GC/MS after derivatization under stable apparatus conditions using (1) target tuning, (2) RT locking technique, and (3) automatic derivatization and injection by a robotic platform. The RTs and EI mass spectra were obtained from an existing authorized database. A quantifier ion and one or two qualifier ions were selected for each target metabolite. The calibration curves were obtained as plots of the peak area ratio of the target compounds to an internal standard versus the target compound concentration. These data were registered in a database as a novel CCLD. We examined the applicability of CCLD for analyzing human plasma, resulting in time-saving and labor-saving semi-qualitative screening without the need for standard substances.


1986 ◽  
Vol 32 (2) ◽  
pp. 325-328 ◽  
Author(s):  
V A Soo ◽  
R J Bergert ◽  
D G Deutsch

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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