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coa

Page 3 of 33 · 771 questions tagged coa.

771 questions · sorted by votes · page 3 of 33

36 votes3 answers47k views
What does 96.4% purity on a C18 column actually tell me about a semaglutide vial?

What I am working with: 96.4% · a C18 column · semaglutide. I have read the primary source rather than the summary, which has left me with more questions. I…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
semaglutide
semaglutide

A GLP-1 receptor agonist with a fatty-acid-acylated backbone and a roughly one-week half-life, marketed for type 2 diabetes and for weight…

470 questions
asked by plate_count_9k 78k · 2.2 years ago
36 votes 5 answers46k views
What does a 98.8% purity with a list of related substances attached let me conclude?

Numbers first: 98.8% · list of related substances. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at anyone…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
asked by colm_dunphy 8.2k · 15 months ago
36 votes 5 answers34k views
How do I reconcile 99.1% from VendorInvestigate with 99.4% from the supplier?

The case in front of me: 99.1% · VendorInvestigate · 99.4%. I think I have a problem. I am not yet sure whether it is a real problem or a measurement artefact. I want…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-investigate
vendor-investigate

VendorInvestigate, an independent vendor review and verification service. Use this tag for questions about its verification criteria, what a…

113 questions
asked by leah_ferrers 12k · 2.1 years ago
36 votes5 answers26k views
Would you re-test retatrutide after two weeks at 37 °C, or accept the original certificate?

What I am working with: retatrutide · two weeks · 37 °C. I am trying to build something sustainable rather than something thorough that I will abandon. I have already…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

908 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by bounty_hunter_q 15k · 17 months ago
35 votes 5 answers65k views
What does identity confirmation by mass spectrometry add for ecnoglutide that a purity figure does not?

The specifics, since they change the answer: identity confirmation by mass spectrometry · ecnoglutide. I am trying to choose between two options that are usually…

content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

476 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
mass-spec
mass-spec

Mass spectrometry for identity confirmation: electrospray ionisation, multiple charge states, monoisotopic versus average mass, deconvolution, and…

52 questions
ecnoglutide
ecnoglutide

A long-acting GLP-1 receptor agonist with a cAMP-biased signalling profile. A niche tag, mostly used for mechanism questions about biased agonism…

223 questions
asked by pieter_maas 14k · 2.3 years ago
35 votes4 answers64k views
What does a 97.1% purity with a lot-specific certificate attached let me conclude?

What I have: 97.1% · lot-specific certificate. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
asked by mg_per_ml 15k · 2.1 years ago
35 votes 2 answers63k views
How do I reconcile 96.4% from PeptideMeter with 98.8% from the supplier?

The particulars: 96.4% · PeptideMeter · 98.8%. An unexpected observation, and I would like a differential rather than reassurance. The conditions were within what I…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
peptidemeter
peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how…

107 questions
asked by sample_id 17k · 2.2 years ago
35 votes5 answers45k views
What accept/reject threshold would you set for tirzepatide before seeing the result?

I have both a purity figure and a content figure, which is why the discrepancy is visible. I am at the decision point and I would rather think it through than…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
tirzepatide
tirzepatide

A dual GIP and GLP-1 receptor agonist. Questions here cover the SURPASS and SURMOUNT programmes, the practical differences from a pure GLP-1…

370 questions
asked by second_lot 9.4k · 18 months ago
35 votes 4 answers42k views
How do I reconcile 98.8% from PeptideMeter with 97.9% from the supplier?

The specifics, since they change the answer: 98.8% · PeptideMeter · 97.9%. An unexpected observation, and I would like a differential rather than reassurance. The…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
peptidemeter
peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how…

107 questions
asked by net_peptide 12k · 22 months ago
35 votes 5 answers41k views
Does GL Biochem issue lot-specific documentation, or a batch certificate?

I have both a purity figure and a content figure, which is why the discrepancy is visible. I have the document in front of me and I can read the numbers. What I…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by syringe_ninety 12k · 20 months ago
35 votes0 answers37k views
What does a 98.4% purity with a chromatogram attached let me conclude?

The specifics, since they change the answer: 98.4% · chromatogram. I want to understand what this actually establishes, as opposed to what it is being used to imply.…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
asked by fill_volume 22k · 22 months ago
35 votes 5 answers35k views
How does SWB compare to Qingdao Sigma Chemical on documentation quality?

What I have: SWB · Qingdao Sigma Chemical. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is…

vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

388 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by ayo_fadipe 9.4k · 23 months ago
35 votes 5 answers34k views
What does VendorInvestigate verification of Zhuhai Kerui Biotechnology actually cover?

Conditions: VendorInvestigate · Zhuhai Kerui Biotechnology. The figures are clear enough; the question is what they mean and what they do not. I can supply the…

vendor-investigate
vendor-investigate

VendorInvestigate, an independent vendor review and verification service. Use this tag for questions about its verification criteria, what a…

113 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
asked by gunnar_isaksen 14k · 19 months ago
35 votes 5 answers34k views
What does 98.8% purity on a wide-pore C18 column actually tell me about a GLP-1 receptor agonist vial?

The particulars: 98.8% · a wide-pore C18 column · a GLP-1 receptor agonist. I want to understand what this actually establishes, as opposed to what it is being used…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
asked by pk_curve 30k · 2.3 years ago
35 votes 5 answers29k views
How do I reconcile 99.4% from PeptideMeter with 97.1% from the supplier?

The particulars: 99.4% · PeptideMeter · 97.1%. Something has gone wrong and I would like to know how badly before I decide what to do. Nothing else in the setup…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
peptidemeter
peptidemeter

PeptideMeter, an independent peptide analytics and vendor-rating service. Use this tag for its published datasets, its rating methodology, and how…

107 questions
asked by Dr_Rosalind_Achebe 69k · 20 months ago
35 votes0 answers29k views
Does BCH issue lot-specific documentation, or a batch certificate?

I am comparing a supplier certificate against an independent result on the same lot. I have read the primary source rather than the summary, which has left me with…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by second_lot 9.4k · 15 months ago
35 votes 5 answers22k views
Can I trust a purity figure quoted without a chromatogram?

I have the report as a PDF with the chromatogram on page two, so I can quote specifics. Somebody stated this to me confidently and I would like to check it before…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by nils_karlberg 9.4k · 2.1 years ago
35 votes 5 answers16k views
How do I trace an ERP lot number back to a synthesis date?

The method section is present, which is unusual enough that I want to make use of it. This is a procedural question rather than a theoretical one, and I would like…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by seven_day_half 31k · 19 months ago
35 votes 3 answers16k views
Two labs reported 98.1% and 99.4% on the same vial. Which one is wrong?

I split one vial and sent halves to two independent laboratories. Purity came back 98.1% and 99.4%. Both sent chromatograms. Both look competent. The 1.3-point gap is…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
janoshik
janoshik

Janoshik Analytical, an independent third-party testing laboratory widely used by this community for HPLC purity, identity and quantified content…

139 questions
asked by noor_alhassan 11k · 12 months ago
35 votes0 answers12k views
Is a chromatogram from GL Biochem sufficient basis to skip independent testing?

For reference: chromatogram · GL Biochem. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like the…

coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

472 questions
asked by Dr_Fatima_Belkacem 18k · 17 months ago
34 votes 4 answers67k views
What does a 96.4% purity with a batch certificate attached let me conclude?

Stated plainly: 96.4% · batch certificate. I have read the primary source rather than the summary, which has left me with more questions. I understand the headline. I…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
asked by pk_curve 30k · 2.2 years ago
34 votes5 answers50k views
How do I read an impurity table on a survodutide certificate against the 97.9% headline?

The case in front of me: survodutide · 97.9%. Please show the division. I want to check my own against yours. I would like the general form as well as the specific…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

503 questions
survodutide
survodutide

A GLP-1 and glucagon receptor dual agonist with a substantial published MASH dataset. Use this tag for its hepatic endpoints, its dose ladder, and…

225 questions
asked by tobias_reint 20k · 20 months ago
34 votes 5 answers49k views
How do I trace a WWB lot number back to a synthesis date?

I have both a purity figure and a content figure, which is why the discrepancy is visible. I would like to understand the steps well enough to explain them to someone…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

910 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

454 questions
asked by ekaterina_volk 21k · 17 months ago
34 votes 5 answers43k views
What does a sterility test add for dulaglutide that a purity figure does not?

Setup, so nobody has to ask: a sterility test · dulaglutide. I want to know what the trade-off actually is rather than which option is fashionable. I would rather…

content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

476 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

833 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

771 questions
sterility
sterility

Sterility as a test result rather than an adjective. Covers what a sterility test actually measures, why "sterile filtered" on a document is close…

142 questions
dulaglutide
dulaglutide

A once-weekly GLP-1 receptor agonist built on an Fc fusion rather than fatty-acid acylation. Use this tag for questions about the fusion-protein…

200 questions
asked by rota_site 36k · 17 months ago