A high-throughput UPC2-MS/MS method for the separation and quantification of C19 and C21 steroids and their C11-oxy steroid metabolites in the classical, alternative, backdoor and 11OHA4 steroid pathways

In the present study an ultra-performance convergence chromatography tandem mass spectrometry (UPC2-MS/MS) analytical method was developed and validated for the determination of 17 C-19 and 14 C-21 steroids, including C11-oxy C-19 and C11-oxy C-21 steroids. The limit of detection and limit of quantification ranged from 0.01 to 10 ng/mL and from 0.01 to 20 ng/mL, respectively, and the method shows the recovery, matrix effect and process efficiency of steroids isolated from a serum matrix to be within acceptable limits. Good accuracy, repeatability and reproducibility were also shown and the method provided excellent sensitivity and selectivity as stereoisomers and regioisomers were also resolved and quantified accurately. Clinical conditions such as congenital adrenal hyperplasia, polycystic ovary syndrome in females and disorders of sex development in neonates and in children, amongst others, are characterized by abnormal steroid levels. Steroid profiling is essential to accurately diagnose steroid levels in the above settings as well as in androgen excess or deficiency in adrenal-linked endocrine diseases. Our method, separating C-19 and C-21 steroids in a single chromatographic step, offers a reduced sample turnover rate in the clinical setting, while providing comprehensive steroid profiles of in vivo steroids in the nmol/L range. This is, to our knowledge, the first method reported to simultaneously separate C-19 and C-21 steroids, together with their C11-hydroxy and C11-keto metabolites -one which may hold promise in the identification of new steroid markers in steroid-linked endocrine diseases, in addition to profiling steroid metabolism and abnormal enzyme activity in patients.