Lee, Su Hyeon Choi, Man Ho Lee, W.-Y. Chung, Bong Chul 2024-01-20T18:03:59Z 2024-01-20T18:03:59Z 2021-09-02 2010-12 2233-4203 https://pubs.kist.re.kr/handle/201004/130899 Cross reacting antibodies can cause an overestimation of the results of immunoassays. Therefore, alternative methods are needed for the accurate quantification of steroids. Gas chromatography combined with isotope-dilution mass spectrometry (GC-IDMS) is developed to quantify urinary active androgens, testosterone, epitestosterone and dihydrotestosterone, which are clinically relevant androgens to both hair-loss and prostate diseases. The method devised involves enzymatic hydrolysis with β-glucuronidase, solid-phase extraction, liquid-liquid extraction using methyl tert-butyl ether and subsequent conversion to pen-tafluorophenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive and selective analysis in selected-ion monitoring mode. Flophemesyl-TMS derivatization not only eliminates matrix interference but also has a good peak resolution within a 6 min-run. A selective and sensitive GC technique with flophemesyl-TMS derivatives also allows accurate quantitative analysis of three active androgens when combined with IDMS. The limit of quantification of the three analytes was <50 pg/mL, and extraction recoveries ranged from 91.9 to 102.1%. The precision and accuracy were 1.2~6.5% and 89.0~106.7%, respectively. This GC-IDMS method can be useful for evaluating the drug efficacy and monitoring the biological processes responsible for male-pattern baldness and prostate diseases. English Korean Society for Mass Spectrometry Isotope-dilution mass spectrometry for quantification of urinary active androgens separated by gas chromatography Article 10.5478/MSL.2010.1.1.029 1 Mass Spectrometry Letters, v.1, no.1, pp.29 - 32 Mass Spectrometry Letters 1 1 29 32 scopus ART001912447 2-s2.0-84876891773 Article Androgen Drug efficacy GC-MS Isotope-dilution Testosterone