HPLC and mass spectrometry, explained

The two methods behind every SCALE Performance certificate, in plain terms.

Reverse-phase HPLC

High-performance liquid chromatography pushes a dissolved sample through a packed column. In reverse-phase HPLC the column is water-repelling, so compounds separate by how strongly they stick to it as the solvent becomes more organic. Each compound leaves the column at a characteristic retention time and is recorded as a peak.

LC-MS

LC-MS couples liquid chromatography to a mass spectrometer. Electrospray ionization turns molecules into charged ions and measures their mass-to-charge ratio. Peptides often carry several charges, producing a series of peaks that software converts back to a single molecular mass. That mass is compared with the value calculated from the sequence.

Why both

HPLC answers how much of the sample is one thing. Mass spectrometry answers what that thing is. Together they confirm both purity and identity.