Application of Liquid Chromatography/LTQ Linear Ion Trap Mass Spectrometry for Quantifying the Biomarkers Creatinine and Cortisol in Serum

Abstract Random metabolites present in a complex matrix can be characterized and quantified by a fast and robust liquid chromatography/mass spectra (LC/MS) method using the LTQ linear ion trap MS system. The experimental results showed excellent selectivity, precision, and sensitivity. The LTQ linear ion trap MS was found to be an excellent and highly selective instrument for measuring metabolites such as creatinine and cortisol present in complex matrices, even when such analytes were present at trace levels.