Comparison of evaporation techniques for the preparation of salivary cortisol for analysis by liquid chromatography-electrospray tandem mass spectrometry.
Compare evaporation techniques in the work-up procedure of saliva samples for cortisol analysis by a previously validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Samples were evaporated using freeze drying, centrifugal concentration, and nitrogen flow and analyzed by LC-MS/MS. Cortisol concentrations detected using each technique did not significantly differ. Factors other than the recovery of cortisol were evaluated. Evaporation using freeze drying/centrifugal concentration is an automated process, reducing overall processing time for analysis of numerous samples.