Qualification and quantification of seventeen natural steroids in plasma by GC-Q-MS and GC-IT-MS/MS.

Studying the plasma steroid profile offers information about the possible existence of endocrinological alterations. This study describes the development and validation of gas chromatographic-mass spectrometric and gas tandem mass spectrometric methods for the simultaneous identification of 17 steroid hormones in human plasma using five different solvents. The n-hexane/ethyl acetate solvent mixture, in a proportion of 70/30 (v/v) provided the best results. The extracts were derivatized with N-methyl-N-trimethylsilyl-trifluoroacetamide. The obtained limits of detection were below 1 ng/mL in the majority of the studied steroids and the limits of quantification were below 5 ng/mL; the method obtained good linearity, reproducibility, repeatability, accuracy and recoveries above 95% in most cases.