Mass Spectrometry

يُعرف أيضًا باسم: MS, ESI-MS

Mass spectrometry confirms a peptide’s molecular weight, verifying its amino-acid sequence identity by measuring the mass-to-charge ratio of ionized molecules.

In electrospray ionization mass spectrometry (ESI-MS), the sample is converted into charged gas-phase ions whose mass-to-charge ratio is measured by the analyzer. The instrument reports the molecule’s mass, which is compared against the theoretical mass calculated from the intended amino-acid sequence.

A close match within a narrow tolerance confirms sequence identity, while a significant deviation can indicate a wrong, truncated, or modified peptide. Because HPLC measures how much target compound is present and mass spectrometry confirms what that compound is, the two are reported together on a certificate of analysis as complementary purity and identity data.