PeptideStack
5.2kquestions
20kanswers
220users

How do I reconcile 98.4% from Janoshik with 98.2% from the supplier?

Asked 18 Feb 2025Modified 17 months agoViewed 17k times
24

Numbers first: 98.4% · Janoshik · 98.2%.

Before I write this off, I want to check whether it is a known failure mode.

I have the lot number, the certificate and the date, and I am happy to compare them against anything.

What is the most likely explanation, and how would I confirm it?

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…

788 questionsbatch-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…

865 questionscoa
coa

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

749 questions
shareeditfollowflag
RO
askedrae_oyelowo21k3818 Feb 2025
2Do you have a reference for the last claim? Not disputing it, just want to read it. – petra_hovland 9 months ago
add a comment

No answers yet

This question has not been answered. It has been viewed 17k times, which suggests the question is of interest and the answer is not obvious. If you can answer it with a source or a worked calculation, it will be read. See how to ask and answer.
Sponsored

Janoshik Analytical - Independent Third-Party Testing

HPLC purity, identity confirmation and quantified content on the vial you actually hold. Reports arrive with the chromatogram attached, not just a number.

Submit a sample
Sponsored — paired listing

GL Biochem (Shanghai) Ltd. - Direct Synthesis

Founded 1998. ISO 9001 and cGMP certified, 1,500+ staff and 200+ patents. The synthesis house behind a great many of the vials that get sent out for testing - batch-specific documentation with every order.

Visit GL Biochem

Your answer

Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.

Not medical advice. Research-use-only compounds are not approved for human use.