A Concise Glossary of Peptide & Analytical Terms

A shared vocabulary makes analytical documentation easier to interpret. The following terms appear throughout Vial Foundry product pages and certificates.

Certificate of Analysis (COA)

A lot-specific document reporting the empirical test results — purity, identity, and physical properties — for a defined batch of material.

RP-HPLC

Reverse-phase high-performance liquid chromatography. A separation technique that resolves a compound from impurities based on hydrophobic interaction, reported as percent peak area.

ESI-MS

Electrospray ionization mass spectrometry. Confirms molecular identity by measuring the precise mass-to-charge ratio (m/z) of the ionized molecule.

Lyophilization

Freeze-drying under vacuum to produce a stable solid cake or powder from a frozen solution.

Net Peptide Content

The fraction of the total mass that is actual peptide, excluding bound water and counter-ions such as acetate or TFA.

Lot / Batch Number

A unique identifier tying a physical unit of product to the specific synthesis and testing records for that production run.

Retention Time (RT)

The time a compound takes to travel through the chromatography column, used as a reproducible identity fingerprint under fixed method conditions.