An automated Immunoaffinity liquid chromatography-tandem mass spectrometry assay for quantification of aldosterone in human plasma.

The diagnosis of primary aldosteronism (PA) relies on the accurate determination of aldosterone. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has long been considered the gold standard for aldosterone quantification but it is hindered by labor-intensive sample preparation. To address this, we developed an immunoaffinity-mass spectrometry (iMS) assay on a fully automated device combining anti-aldosterone antibodies with stable isotope-labeled internal standards (IS).