Specification language connects scientific description with purchasing decisions. Identity, purity, peptide content, water content and counterion information describe different aspects of a material and should not be collapsed into a single quality number. This guide explains the role of those terms without assuming that every test is available for every product. The relevant specification and analytical documents determine which fields apply to an individual material and how each result should be understood.
Purity and content answer different questions
A chromatographic purity result describes the proportion of the measured signal attributed to a component under the stated method. It is not automatically the mass fraction of peptide in the entire weighed material. Water, counterions and other components may need separate consideration. When a document reports peptide content, retain the stated method and basis rather than relabeling it as purity.
Identity, form and method belong together
Identity information describes the expected material, while analytical methods provide particular kinds of evidence about a sample. The salt or counterion form, where specified, is part of the material description. Method names alone do not establish that a test was performed on the relevant batch, so the record should link any claimed result to the original document.