The coming of age of liquid chromatography coupled to tandem mass spectrometry in the endocrinology laboratory

Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been rapidly incorporated in the routine of the endocrinology laboratory. Most endocrinologists are aware of the benefits afforded by this technique and tandem mass spectrometers are clearly no longer a mere research method but an important tool widely used for diagnosis. In the last 15 years, LC-MS/MS has replaced techniques such as immunoassay and HPLC for the analysis of hormones because it provides higher specificity and good sensitivity. Also, it permits simultaneous measurement of several analytes and sample preparation and acquisition are fast and simple. Although several strategies based on LC-MS/MS have been described in the last 15 years, there is still room for improvement. The impact of matrix effects and isobaric interferences have been addressed by only a few studies, and standardization with reference materials is available for a limited number of analytes. This review summarizes the application of LC-MS/MS in analyzing three classes of hormones: steroids, derivatives of the aromatic amino acids, and peptides and proteins. The benefits and current limitations of LC-MS/MS will be discussed for these hormone categories.