Study on dissolution mechanism of cortisol and cortisone from hair matrix with liquid chromatography–tandem mass spectrometry

Abstract

BackgroundHair cortisol has been used as a biomarker of chronic stress. The detected contents of hair cortisol might depend on the incubation duration in solvents for no-milled hair samples with 3-layer structure. However, there was no research on the dissolution mechanism of hair analytes. MethodsAfter uniform mixture, no-milled hair samples were incubated in methanol and water for the 12 different durations and milled hair was done as comparison. Hair cortisol and cortisone were determined with high performance liquid chromatography–tandem mass spectrometry (LC–MS/MS). ResultsThe measured concentrations of hair cortisol and cortisone showed ≥2 maxima during the entire incubation in methanol and water from 5min to 72h for no-milled hair. Hair cortisol concentration measured by LC–MS/MS was increased with the incubation duration. Conversely, it was not held when hair was powdered prior to the incubation in methanol. ConclusionsHair cortisol and cortisone were dissolved from hair matrix through the 2-stage or multistage mechanism, which might depend on the hair 3-layer structure and its degree of damage.