TinaHashiRN said:My vendor review relevant to certificates of analysis: ordered 4 times from my current compounder.
Adding a me-too, because a thread of one person's experience is not much use. Nothing to add that would improve it.
Dr.PulmRoch said:HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean: Purity %: Should be…
Reconstituted peptide stability data for certificates of analysis: I had Janoshik test my reconstituted vial at day 1, day 14, and day 28 stored in the refrigerator.
Day 1: 99.2% purity
Day 14: 98.1% purity
Day 28: 97.0% purity
Minimal degradation over 28 days when properly refrigerated. This confirms the standard 28-day beyond-use date is appropriate. Beyond 28 days, I'd reconstitute a fresh vial to be safe.
Dr.PulmRoch said:HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean: Purity %: Should be…
Mass spectrometry confirmation for certificates of analysis: beyond HPLC purity, mass spec tells you the molecule's exact molecular weight. This confirms identity — not just purity.
Why this matters: HPLC can show you a "pure" compound, but if it's pure of the WRONG compound, purity is meaningless. Mass spec at m/z 4113.58 Da confirms it's actually semaglutide. My Janoshik report includes both HPLC and mass spec.
If your testing provider only offers HPLC, consider upgrading to include mass spec for at least your first batch from a new vendor.
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Shop Reference StandardsDr.PulmRoch said:HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean: Purity %: Should be…
Saving this. It is the first explanation that did not require me to already understand it. Sending this to two other people who asked me the same thing last week.
Moderator note: two posts asking for a source have been merged into one. Please search the thread before asking again. Thread quality here is what the rules are for. Keep it up.