Liquid chromatography–mass spectrometry (LC-MS/MS) is simply HPLC (high-performance liquid chromatography) with two mass spectrometry (MS) detectors. The liquid chromatography (LC) part of LC-MS separates compounds within a sample and the mass spectrometer provides mass to charge ratio data which can help provide structural identity of the compound.
The bioanalysis capabilities of LC-MS/MS can add specificity and reproducibility for certain applications with low-level concentration biomarker testing that may be less suitable for immunoassay. This technology works well for the analysis of organic and biochemical compounds found in complex biological matrices.