batch

The title is the whole question — do related substances actually matter or is it forum lore at this point — but here is why I am asking. The PDF creation date being…

Asking properly rather than in a comment on somebody else’s thread: can we stop arguing about below spec until somebody posts a number. On inter-lab disagreement, which…

the Janoshik rule is doing its job and people should stop complaining — posting the reasoning in public because a policy you cannot inspect is just a preference. Tested…

the purity advice in here is 3 years out of date. It is the sort of thing everyone half-believes and nobody writes down. Hard numbers: 3 years. Anything softer than…

Slightly embarrassed to be asking this, but: help me understand COA, I have read the wiki twice. My first certificate had a compound name, a percentage and a logo. I…

the related substances advice in here is 2 years out of date — a position I have arrived at slowly and would like tested. To save the first four comments: 2 years. Net…

vendor COA says 99.2%, my Janoshik came back 97.4%. who is wrong, and before anyone asks: same batch throughout, single submission, no cherry-picking between services.…

the PeptideMeter advice in here is 2 years out of date. Making the case below, and I expect to lose some of it in the comments. To save the first four comments: 2…

Slightly embarrassed to be asking this, but: certificate of analysis — what am I missing here. Spent four months confusing area% and mass% in every post I made here.…

6th independent test on HJ — 99.1% on a claimed 99.0%, and the trend is the interesting part. One vial, one service, one member paying, which is the only kind of result…

two reta batches, two services, 98.4% and 97.9%, and before anyone asks: same batch throughout, single submission, no cherry-picking between services. 98.4% and 97.9%.…

we are measuring batch at the wrong time and calling it noise — a position I have arrived at slowly and would like tested. On inter-lab disagreement, which generates…

COA — 5 things I got wrong before I got it right — a position I have arrived at slowly and would like tested. LC-MS gives you identity; UV purity gives you a relative…

The title is the argument: related substances — 9 things I got wrong before I got it right. Here is the rest of it. The PDF creation date being later than the analysis…

Proposal, not a decision: proposal — a flair for Medutest posts. If the report gives a mass spectrum as well as UV purity, say so. Identity and relative quantity are…

Genuine question, and the title is the question: how much of what we believe about COA actually comes from area percent threads. My first certificate had a compound…

batch is not what most of this community thinks it is. It comes up every few weeks and the answer has not changed. The document I was worried about turned out to be a…

Posting this as a discussion rather than a claim: unpopular opinion: most of what gets said here about purity is guesswork. LC-MS gives you identity; UV purity gives…

Posting this because the title is the whole finding — JEEP vs WXT on the same compound, same month — both cleared 98.5% — and a number without its method is a rumour.…

Short public-service post: the four things a COA must have or it is decorative. Asked CPC for the batch-specific certificate and had the full document — batch, date,…

Right: Homopeptide vs QSC on the same compound, same month — both cleared 98.0%. I paid for this one myself, nobody sent me anything, and the receipts are in the…

we are measuring area percent at the wrong time and calling it noise. Not a hot take, just something I have not seen said plainly here. Net peptide content is the…

identical chromatogram on two different compounds from the same vendor. Order-by-order, with dates, because vibes are not data. My first certificate had a compound…

identity and quantity are two questions and most COAs answer one. It is the sort of thing everyone half-believes and nobody writes down. Asked for the storage condition…

The title is the argument: reading test results threads from 2024 and half of it aged badly. Here is the rest of it. Have now spent more on testing than on some of the…