Abstract
Monitoring urinary free cortisol (UFC) excretion helps assess adrenal function and is used to screen for endogenous Cushing's syndrome caused by an adrenal or pituitary tumor. While serum cortisol levels fluctuate in response to time of day, stress, and concentrations of cortisol-binding globulin (CBG), a 24-h urine collection measures the cortisol produced over the entire day and does not suffer from as much variability as a serum measurement.We describe here a method of measurement of urinary free cortisol (UFC) and cortisone using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine samples, combined with stable isotope-labeled internal standards, are extracted by liquid-liquid extraction using ethyl acetate and hexane. An API 5500 mass spectrometer operated in positive atmospheric pressure chemical ionization (APCI) mode is used for detection.
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.