GLPHubglpresearchhub.com
Read-only archive. GLP Research Hub is a static community record — nothing here is for sale, no account is needed, and no vote you cast is counted. Why?
Single comment threadYou are looking at one branch of which fields turn a COA from a specification into a result — 9 comments in the full submission. View in context.
164
c/coa·submitted 8 days ago by u/tuva_aalto

which fields turn a COA from a specification into a result

Questionbranch of 6 comments

which fields turn a COA from a specification into a result. Change my mind, genuinely — I have no stake in being right about this. Water content 3.8%, acetate 6.2%, purity 99%, net peptide about 90% of label weight. All four numbers honest, and I had to read it twice. Spent four months confusing area% and mass% in…

Read the full submission and all 9 comments →

This branch

6 comments, started 7 days ago
u/stablecoin_steve20 points·7 days ago

Net peptide content is the fraction of the powder that is actually peptide once counterion, water and residual solvent are accounted for. A 99% pure acetate salt can still be about 85% peptide by mass.

replysharereportpermalink
u/tuva_aaltoOP11 points·7 days ago·edited

Does the lot on the vial match the lot on the page?

replysharereportpermalink
u/ahmed_rasmussen-12 points·6 days ago

redact your own name, never the batch details

replysharereportpermalink
u/sig_figs_sammod · analytical5 points·6 days ago

Does the lot on the vial match the lot on the page?

This is the sentence to take away. The rest of the thread is footnotes to it.

replysharereportpermalink
u/anders_kuusela13 points·7 days ago

Started keeping a folder of every certificate I have been sent. The ones that itemise impurities are a small group and they are mostly the same suppliers.

replysharereportpermalink
load more comments (1) →

← back to the whole thread

About c/coa

How to read a certificate of analysis and what it does and does not tell you. Area% versus mass%, identity versus quantity, water content, related substances, acetate counterions, and the difference between a vendor-supplied COA and an independent test on the vial you actually received.

71kmembers
130submissions
Aug 2023created
submissions / month, last year
Sponsored

Janoshik Analytical

Independent HPLC and mass spec. The number you get is the number they found.

janoshik.comSponsored

GL Biochem (Shanghai)

Custom peptides and amino acids direct from the manufacturer since 1998. ISO 9001 / cGMP. Batch COA every order.

glbiochem.net
More in c/coa
c/coa rules
  1. Post the full document. Cropped COAs that hide the batch number or date get removed.
  2. Redact your own name and order id, not the vendor's batch details.
  3. No "is this good?" without saying what the compound and claimed purity are.
  4. Independent community. Nobody here sells anything, and anyone who tries is banned.
  5. Not medical advice. Describe what you did; never prescribe to a stranger.
  6. Claims need evidence. Batch numbers, dated screenshots, independent test reports, or a citation.
  7. No referral links, discount codes or affiliate URLs. Permanent ban, no appeal.
  8. No contact handles, wallet addresses or tracking numbers — they identify people.
  9. Be recognisably decent. Disagree hard, insult nobody.
Full rules and how they are enforced →
Moderators
u/coa_janitoru/purity_pedantu/coa_collectoru/certified_referenceu/first_hundred
Volunteers. Unpaid, unaffiliated, and reachable through modmail only.
Before you read on

Several compounds discussed on GLP Research Hub are sold for research use only and are not approved for human use anywhere. Nothing here is medical advice and none of it is written by your clinician. If a post reads like an instruction, treat it as a description of what one stranger did.

Full disclaimer →