HPLC separates components.
High-performance liquid chromatography separates compounds in a sample as they travel through a column. A detector records the resulting peaks. The relative area of a target peak is commonly used to report chromatographic purity under the stated method.
LC-MS supports identity.
Liquid chromatography–mass spectrometry combines separation with mass analysis. The measured mass-to-charge information can help determine whether the target compound is present and consistent with its expected molecular characteristics.
The methods are complementary.
HPLC can provide a purity profile, while LC-MS can add identity evidence. Neither result should be read without the method, sample identification, and reporting context shown on the full laboratory document.