A rapid liquid chromatography-tandem mass spectrometry method for the analysis of urinary 5-hydroxyindoleacetic acid (5-HIAA) that incorporates a 13C-labelled internal standard:

BackgroundUrinary 5-hydroxyindoleacetic acid (5-HIAA) is a first-line investigation for gastrointestinal neuroendocrine tumours that secrete serotonin. It also has clinical utility for monitoring d...