From the other side of the consultation, briefly.
HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean:
- Purity %: Should be >97%. Below 95% is concerning.
- Retention time: Should match reference standard for the peptide
- Related substances: Degradation products should be <2% total
- Single impurity: No individual impurity should exceed 1%
My last batch: 99.6% purity, 0.0% total related substances. Clean chromatogram with single sharp peak at expected retention time. Exactly what you want to see.
Following on from ZaraB_AL — and this may be the naive question:
Was that from a primary source or from a summary of one?
ingrid_STO said:HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean: Purity %: Should be…
Vendor quality matters when discussing certificates of analysis. I've tested my last 3 batches through Janoshik and purity has ranged from 99.6% to 99.4%. Consistency is key.
For anyone new: always request the COA, and consider independent verification. The $300 for a Janoshik test is worth the peace of mind.
Janoshik Analytical — Independent Testing
Trusted third-party HPLC & mass spectrometry analysis. Verify peptide purity with the lab the community relies on. Independent. Accurate. Transparent.
Verify Your PeptidesGL Biochem (Shanghai) Ltd. — Direct Manufacturer
Est. 1998. The synthesis house behind the vials you send for testing. ISO 9001 and cGMP certified, 1,500+ staff, batch-specific COA with every order.
Browse GL Biochemingrid_STO 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: 99.6% purity
Day 14: 98.4% purity
Day 28: 99.2% 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.
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