Amino acid analysis gives content: it hydrolyses the peptide and quantifies the residues. It measures the peptide content independent of chromatographic purity. Very few supplier certificates report it.
31 likes 10mo
Topic summary
Batch date after test date, and other internal inconsistencies
This is a generated summary. It shows the 5 most-liked posts from a topic of 32, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.
Worth separating two things that the opening post runs together.
Endotoxin testing is separate: a certificate of purity says nothing about endotoxin. A chemically pure preparation can carry a clinically significant endotoxin load. If endotoxin matters, it needs to be tested and reported.
16 likes 10mo
t.brandt, post #3: Worth separating two things that the opening post runs together. Endotoxin testing is separate: a certificate of purity says nothing about endotoxin. A chemically pure preparation can carry a clinically significant endotoxin load. If endotoxin matters, it needs to be tested and reported. Go to post
On post #3 — agreed on the reasoning, with one qualification.
Purity and content are different measurements: purity tells you what proportion of the detected material is the intended species. Content tells you how much of the intended species is present in the container. A lyophilised vial can be 99% pure and contain considerably less than the label claims because the remainder is water, counter-ion and excipient.
On post #14 — agreed on the reasoning, with one qualification.
Endotoxin testing is separate: a certificate of purity says nothing about endotoxin. A chemically pure preparation can carry a clinically significant endotoxin load. If endotoxin matters, it needs to be tested and reported.
18 likes 8mo
Amino acid analysis gives content: it hydrolyses the peptide and quantifies the residues. It measures the peptide content independent of chromatographic purity. Very few supplier certificates report it.
19 likes 8mo
Read the full topic (32 posts)
This topic was referenced in
- About the COA interpretation categoryAnalytics › COA interpretation · 12 replies
- Reused chromatograms across lots: how to spot itAnalytics › COA interpretation · 60 replies
Suggested topics
| Topic | Participants | Replies | Views | Activity |
|---|---|---|---|---|
|
Counter-ion form: the field almost nobody reports
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 | |
|
Specification in the result column: why that is a meaningful error
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 |
|
Revisiting: A field-by-field walk through a certificate of 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 |
|
Counter-ion form: the field almost nobody reports — one year on
On the subject in the title: Counter-ion form: the field almost nobody reports — one year on Working notes rather than a conclusion. A documentation question rather than an analytical one. I have a…
|
+121 | 139 | 31k | 16mo |
|
Certificates issued by the seller versus by a laboratory
Posting this under the heading it deserves: Certificates issued by the seller versus by a laboratory Everything below is what sits behind that. I would like to understand what this number means before I…
|
+58 | 65 | 1.2k | 15mo |
Related topics — sharing the tags certificate of analysis, reference standards, batch & lot numbers
| Topic | Participants | Replies | Views | Activity |
|---|---|---|---|---|
|
Second pass at: Certificates issued by the seller versus by a laboratory
Second pass at: Certificates issued by the seller versus by a laboratory — setting out what I have, and where I think it stops being reliable. A documentation question rather than an analytical one. I have a…
|
+81 | 92 | 20k | 18mo |
|
What a simple presence test is genuinely useful for
What a simple presence test is genuinely useful for — that is the question, and I have not found it answered plainly anywhere I have looked. Working through the identity arithmetic and I would like it…
|
2 | 58 | 1d | |
|
A supplier who responds to a discrepancy with silence
On the subject in the title: A supplier who responds to a discrepancy with silence Working notes rather than a conclusion. Structured report rather than an opinion, following the format the maintainers asked…
|
2 | 6.1k | 16mo | |
|
Second pass at: Why chargeback is not the safety net people assume
Second pass at: Why chargeback is not the safety net people assume Writing it up because I had to work it out twice and would rather nobody else did. A logistics question, since the answers here are usually…
|
2 | 25k | 3mo | |
|
What "verified" means on our vendor pages, stated narrowly
What "verified" means on our vendor pages, stated narrowly — that is the question, and I have not found it answered plainly anywhere I have looked. I would like to talk about documentation quality as a…
|
+27 | 31 | 27k | 7mo |