Reference

Quantitative determination of methyltestosterone and methyltestosterone-d3 in serum by gas chromatography-mass spectrometry

Quantitative determination of methyltestosterone and methyltestosterone-d3 in serum by gas chromatography-mass spectrometry. Shinohara, Y.; Baba, S.; Kasuya, Y. (Tokyo Coll. Pharm., Hachioji 192-03, Japan). J. Chromatogr., 338(2), 281-8 (English) 1985. CODEN: JOCRAM. ISSN: 0021-9673. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) A method for the quant. estn. of methyltestosterone [58-18-4] and methyltestosterone-d3 [96425-03-5] in biol. fluids was developed using gas chromatog.-mass spectrometry-selected-ion monitoring. Methyltestosterone-d6 was used as an internal std. Methyltestosterone and methyltestosterone-d3 in serum were detd. based on the peak height ratios of the mol. ions of methyltestosterone, methyltestosterone-d3, and methyltestosterone-d6. The sensitivity of the assay was 50 pg. For 2.01-200.72 mg methyltestosterone-d3/mL added to human serum, the accuracy of the assay was 0.6-2.9%. The day-to-day precision for 4.99-49.87 ng methyltestosterone/mL was 0.8-4.0% and 0.4-1.8% for 5.03-50.18 ng methyltestosterone-d6/mL.

Prediction of measurement uncertainty in isotope dilution gas chromatography/mass spectrometry

All Rights Reserved. Prediction of measurement uncertainty in isotope dilution gas chromatography/mass spectrometry. Hasegawa, Hiroshi; Shinohara, Yoshihiko; Hashimoto, Takao; Matsuda, Rieko; Hayashi, Yuzuru (School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan). Journal of Chromatography, A, 1136(2), 226-230 (English) 2006 Elsevier B.V. CODEN: JCRAEY. ISSN: 0021-9673. DOCUMENT TYPE: Journal CA Section: 80 (Organic Analytical Chemistry) An equation is theor. derived which describes the relative std. deviation of the amt. ratios of analyte to its isotope-labeled variant in gas chromatog./mass spectrometry (GC/MS) using the stable isotope diln. 96425-03-5 and 58-18-4 which are cas registry numbers are also used here. method. The detn. of methyltestosterone is taken as an example. The uncertainty equation proposed is justified by comparing the theor. relative std. deviation values with the exptl. relative std. deviation values obtained by replication over a wide range of analyte amt. The detection limit and quantitation limit are estd. from the continuous plot (precision profile) of the theor. relative std. deviation against analyte amt. .