Abstract: | Cortisol is thermally unstable. It is easily decomposed by loss of ketence and water. The spectrum of the resulting 11β-hydroxy-Δ4-androsten-3,17-dion can be superimposed upon the spectrum of the undecomposed cortisol, which only can be obtained free of the decomposition product under carefully controlled conditions. The thermal degradation product can be eaisly detected by its molecular peak at mass 302 and a key fragment at mass 163, which are nearly absent in the spectrum of cortisol. Cortisol is therefore an excellent testing material for the quality of inlet systems. |