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 three years of related substances threads, summarised so you do not have to read them — 39 comments in the full submission. View in context.
2.3k
c/coa·submitted 7 months ago by u/sofia_ferreira

three years of related substances threads, summarised so you do not have to read them

Explainerbranch of 8 comments

three years of related substances threads, summarised so you do not have to read them, and I am aware this is a minority view on this board. UV at 214nm sees the peptide bond and picks up almost everything; at 280nm you are looking at aromatics only. Which wavelength the number came from is part of the number. LC-MS…

Read the full submission and all 39 comments →

This branch

8 comments, started 7 months ago
u/liv_nkemelu108 points·7 months ago

Right, and net peptide content is where the counterion and the water go. Both numbers can be honest and very different.

replysharereportpermalink
u/sofia_ferreiraOP69 points·7 months ago

the related substances line is where the story is

replysharereportpermalink
u/noor_cardoso159 points·7 months ago

My first certificate had a compound name, a percentage and a logo. I thought that was normal. It is not, and now I know what to ask for.

replysharereportpermalink
u/andres_restrepo0 points·7 months ago

My first certificate had a compound name, a percentage and a logo.

noor_cardoso has the distinction right — one is a fraction of the detector signal, the other is a fraction of the mass.

replysharereportpermalink
u/certified_referenceMOD65 points·7 months ago

Reminder: a question about a document is not an accusation about a supplier, and posts that blur the two get retitled.

replysharereportpermalink
u/ismael_eriksen18 points·7 months ago·edited

water content is on there and everyone skips it

replysharereportpermalink
[deleted]43 points·7 months ago

[deleted]

replysharereportpermalink
u/sofia_ferreiraOP29 points·7 months ago

the lot on the vial has to match the lot on the page

replysharereportpermalink

← 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

PeptideMeter Analytics

Independent testing plus vendor-level trend data. Community-funded, unaffiliated.

peptidemeter.com
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 →