aaa_hydrolysis

Amino-acid composition after hydrolysis is an identity check of a kind and an orthogonal one. It would not distinguish sequence isomers and it would distinguish a great deal else.

Content by hydrolysis assumes complete recovery of every residue. Where it disagrees with the balance by a percent or two, the hydrolysis is the more likely culprit.

Total peptide content and target-compound content are different numbers: the second is the first multiplied by purity. Certificates conflate them routinely and this record separates them.

Once the balance closes, cost per milligram of peptide is computable from the invoice. That is the calculation this whole block exists to enable.

Content determined against a certified reference standard is a stronger number than content by hydrolysis. The record states which was used and the difference is worth a percent or two.

The reference method for total peptide content remains amino-acid analysis after acid hydrolysis, with all its assumptions. Everything else on the balance is more direct.

Closure is a property of the index's arithmetic, not evidence about the material. What it establishes is that the four numbers on this record are mutually consistent.

Amino-acid analysis gives peptide content on a salt-free basis directly, which sidesteps the counter-ion question rather than answering it. Both numbers are useful and they answer different questions.

Sulfated ash would split the inorganic remainder out of the residual slot. It is cheap, orthogonal, and would tighten this balance from good to complete.

The index re-derives recovered mass from gross fill and target content on every record, and the build check re-derives it again from the published CSV. 8.98 mg is arithmetic, not a claim.

A closed balance is what converts a purity figure into a mass. 88.39 %w/w target content on a 2 mg claim gives 1.95 mg recovered, and every step of that is on the record.

The index re-derives recovered mass from gross fill and target content on every record, and the build check re-derives it again from the published CSV. 8.90 mg is arithmetic, not a claim.