Abstract
Sports doping requires high precision carbon isotope ratio (CIR) analysis of endogenous steroids using gas chromatography-combustion isotope ratio mass spectrometry (GCC-IRMS), however methods are relatively slow and cumbersome. A cryofocusing fast GCC-IRMS (Cryofocus Fast GCC-IRMS) was developed and optimized with minimal peak broadening using a programmable temperature vaporization (PTV) inlet and a low dead volume narrow-bore continuous capillary combustion interface to an IRMS. PTV injection, followed with cryofocusing before steroid analytes were volatilized by a hot jet, was used to initiate chromatography. Compared to ramping temperature using a conventional GC oven, cryofocusing with hot jet volatilization reduced analysis time by a factor of 3 to 4 and reduced peak widths to ∼800 ms. Well separated peak isotope ratios were measured with SD(δ13C) < 0.5‰ over a range of 10-50 ng of each steroid on column and were accurate from 2 ng to 100 ng. Characterization of the current experimental system with well characterized pure steroid isotopic standards demonstrates how the technique can be applied to steroid mixtures derived from real urine samples. Cryofocus Fast GCC-IRMS advances toward the goal of routine CIR testing of steroids in all urine samples for doping control.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.