Tags · Sourcing

certificate of analysis

The document a supplier issues for a batch.

49 topics 14 solved Group: Sourcing

49 topics · page 1 of 2

Topic	Participants	Replies	Views	Activity
Coming back to: Batch date after test date, and other internal inconsistencies Analytics › COA interpretation reference standards amino acid analysis documentation quality certificate of analysis On the subject in the title: Batch date after test date, and other internal inconsistencies Working notes rather than a conclusion. I would like to understand what this number means before I repeat it…	+21	27	420	3h
Reused chromatograms across lots: how to spot it Analytics › COA interpretation batch & lot numbers amino acid analysis documentation quality certificate of analysis On the subject in the title: Reused chromatograms across lots: how to spot it Working notes rather than a conclusion. A documentation question rather than an analytical one. I have a certificate in front of…	+53	60	9.5k	4h
How the vendor documentation pages are maintained, and by whom Sourcing › Vendor reports certificate of analysis Janoshik Analytical batch & lot numbers documentation quality Solved How the vendor documentation pages are maintained, and by whom I have a specific reason for asking rather than idle curiosity, and the context is below. I would like to talk about documentation quality as a…		2	6k	4h
Coming back to: Why our vendor pages link the storefront and mark it sponsored Sourcing › Vendor reports third-party testing batch & lot numbers certificate of analysis documentation quality Why our vendor pages link the storefront and mark it sponsored I have a specific reason for asking rather than idle curiosity, and the context is below. Structured report rather than an opinion, following the…		2	22k	8h
Coming back to: Reconciling a supplier certificate with an independent result Sourcing › Vendor reports documentation quality certificate of analysis batch & lot numbers Posting this under the heading it deserves: Reconciling a supplier certificate with an independent result Everything below is what sits behind that. Structured report rather than an opinion, following the…	+26	30	45k	16h
Reporting a good result: why nobody bothers and why they should Sourcing › Vendor reports third-party testing Janoshik Analytical certificate of analysis batch & lot numbers Reporting a good result: why nobody bothers and why they should — setting out what I have, and where I think it stops being reliable. Structured report rather than an opinion, following the format the…		2	3.5k	17h
Comparing documentation quality across the directory, tabulated Sourcing › Vendor reports third-party testing disputed Janoshik Analytical batch & lot numbers Comparing documentation quality across the directory, tabulated — setting out what I have, and where I think it stops being reliable. I would like to talk about documentation quality as a signal, separately…	+7	11	29k	19h
What a certificate commits its issuer to — one year on Analytics › COA interpretation reference standards certificate of analysis documentation quality batch & lot numbers Wiki What a certificate commits its issuer to — one year on — that is the question, and I have not found it answered plainly anywhere I have looked. A documentation question rather than an analytical one. I have a…	+107	117	6.5k	1d
The report format the maintainers ask for, and why each field is there Sourcing › Vendor reports disputed documentation quality batch & lot numbers certificate of analysis Solved On the subject in the title: The report format the maintainers ask for, and why each field is there Working notes rather than a conclusion. Structured report rather than an opinion, following the format the…		4	6.3k	1d
What a certificate commits its issuer to — the long version Analytics › COA interpretation batch & lot numbers amino acid analysis reference standards certificate of analysis Asking directly, because I could not find a straight answer: What a certificate commits its issuer to — the long version A documentation question rather than an analytical one. I have a certificate in front…	+20	26	21k	2d
[2026 update] A report I filed that turned out to be wrong, and the correction Sourcing › Vendor reports batch & lot numbers third-party testing documentation quality certificate of analysis On the subject in the title: A report I filed that turned out to be wrong, and the correction Working notes rather than a conclusion. Structured report rather than an opinion, following the format the…	+15	19	18k	2d
Follow-up: Reconciling a label claim with a content assay Analytics › COA interpretation reference standards documentation quality batch & lot numbers amino acid analysis Reconciling a label claim with a content assay Writing it up because I had to work it out twice and would rather nobody else did. I would like to understand what this number means before I repeat it anywhere.…	+26	30	6.5k	14d
Purity assay versus content assay: two different numbers Analytics › COA interpretation documentation quality batch & lot numbers reference standards certificate of analysis On the subject in the title: Purity assay versus content assay: two different numbers Working notes rather than a conclusion. I would like to understand what this number means before I repeat it anywhere. A…	+6	10	24k	25d
A checklist for reading a certificate in under two minutes Analytics › COA interpretation certificate of analysis batch & lot numbers amino acid analysis Solved A checklist for reading a certificate in under two minutes — setting out what I have, and where I think it stops being reliable. I would like to understand what this number means before I repeat it anywhere.…	+39	46	38k	1mo
Counter-ion form: the field almost nobody reports Analytics › COA interpretation certificate of analysis documentation quality batch & lot numbers Solved Counter-ion form: the field almost nobody reports Writing it up because I had to work it out twice and would rather nobody else did. A documentation question rather than an analytical one. I have a…		3	11k	2mo
About the COA interpretation category Analytics › COA interpretation certificate of analysis documentation quality batch & lot numbers Pinned Wiki What a certificate of analysis commits its issuer to, which fields matter, and how to spot one that says almost nothing. This post is a community wiki: any member at trust level 3 or above can edit it, and…	+8	12	8.5k	2mo
Revisiting: A field-by-field walk through a certificate of analysis Analytics › COA interpretation certificate of analysis documentation quality reference standards amino acid analysis Revisiting: A field-by-field walk through a certificate of analysis Writing it up because I had to work it out twice and would rather nobody else did. A documentation question rather than an analytical one. I…	+37	41	656	3mo
Second pass at: What "verified" means on our vendor pages, stated narrowly Sourcing › Vendor reports Janoshik Analytical documentation quality third-party testing batch & lot numbers Solved Second pass at: What "verified" means on our vendor pages, stated narrowly — setting out what I have, and where I think it stops being reliable. A logistics question, since the answers here are usually better…	+94	102	20k	3mo
Which fields on a certificate actually matter, ranked Analytics › COA interpretation reference standards certificate of analysis documentation quality batch & lot numbers Closed Which fields on a certificate actually matter, ranked — that is the question, and I have not found it answered plainly anywhere I have looked. Posting the method first, because I know what the first three…	+25	29	46k	4mo
Reconciling a label claim with a content assay Analytics › COA interpretation documentation quality amino acid analysis reference standards certificate of analysis Closed On the subject in the title: Reconciling a label claim with a content assay Working notes rather than a conclusion. I would like to understand what this number means before I repeat it anywhere. A…	+2	6	183	4mo
Specification in the result column: why that is a meaningful error Analytics › COA interpretation reference standards amino acid analysis certificate of analysis batch & lot numbers Under review Closed Posting this under the heading it deserves: Specification in the result column: why that is a meaningful error Everything below is what sits behind that. Working through the identity arithmetic and I would…	+107	129	41k	5mo
Coming back to: "Greater than or equal to 99%" as a specification rather than a result Analytics › COA interpretation documentation quality amino acid analysis certificate of analysis batch & lot numbers Posting this under the heading it deserves: "Greater than or equal to 99%" as a specification rather than a result Everything below is what sits behind that. Working through the identity arithmetic and I…		2	31k	6mo
Batch date after test date, and other internal inconsistencies Analytics › COA interpretation certificate of analysis reference standards batch & lot numbers documentation quality Batch date after test date, and other internal inconsistencies — setting out what I have, and where I think it stops being reliable. I would like to understand what this number means before I repeat it…	+27	31	4.9k	7mo
Water content on a certificate and why it changes the arithmetic — what changed since Analytics › COA interpretation documentation quality batch & lot numbers reference standards certificate of analysis On the subject in the title: Water content on a certificate and why it changes the arithmetic — what changed since Working notes rather than a conclusion. A documentation question rather than an analytical…		3	801	8mo
Reconciling a supplier certificate with an independent result Sourcing › Vendor reports third-party testing Janoshik Analytical certificate of analysis Reconciling a supplier certificate with an independent result — setting out what I have, and where I think it stops being reliable. Structured report rather than an opinion, following the format the…	+18	24	347	9mo
A checklist for reading a certificate in under two minutes — does this still hold? Analytics › COA interpretation documentation quality certificate of analysis amino acid analysis batch & lot numbers Solved A checklist for reading a certificate in under two minutes — does this still hold? — that is the question, and I have not found it answered plainly anywhere I have looked. I would like to understand what this…	+49	55	15k	9mo
When a tidy document is a signal and when it is decoration Analytics › COA interpretation certificate of analysis reference standards batch & lot numbers amino acid analysis When a tidy document is a signal and when it is decoration I have a specific reason for asking rather than idle curiosity, and the context is below. A documentation question rather than an analytical one. I…	+6	10	20k	10mo
[2026 update] A certificate with no method stated: what can you conclude? Analytics › COA interpretation reference standards certificate of analysis documentation quality batch & lot numbers Solved A certificate with no method stated: what can you conclude? — that is the question, and I have not found it answered plainly anywhere I have looked. I would like to understand what this number means before I…		2	82	11mo
When a tidy document is a signal and when it is decoration — does this still hold? Analytics › COA interpretation reference standards amino acid analysis documentation quality certificate of analysis Solved Asking directly, because I could not find a straight answer: When a tidy document is a signal and when it is decoration — does this still hold? A documentation question rather than an analytical one. I have a…	+3	7	22k	11mo
[2026 update] Comparing documentation quality across the directory, tabulated Sourcing › Vendor reports batch & lot numbers documentation quality disputed certificate of analysis Solved Closed On the subject in the title: Comparing documentation quality across the directory, tabulated Working notes rather than a conclusion. I would like to talk about documentation quality as a signal, separately…		3	18k	11mo

Sponsored Janoshik Analytical — independent third-party testingHPLC purity and mass-spectrometric identity on submitted samples, reported with the method stated. The laboratory most often cited in this community’s verification records.Independent testing → Sponsored GL Biochem (Shanghai) Ltd. — synthesis, directFounded 1998. ISO 9001 and cGMP certified, over 1,500 staff and 200-plus patents. Custom peptide synthesis and amino acid derivatives, with a batch certificate on every order.Custom synthesis →