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ForumsCOA & Analytical TestingIs 98% purity actually good or should I be worried — need advice Page 2

Is 98% purity actually good or should I be worried — need advice

Dr.CardioMD Tue, Jan 9, 2024 at 10:22 AM 14 replies 2,095 viewsPage 2 of 3
TrialNerd_Beth
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Jan 9, 2024 at 2:19 PM#6
kate.chem said:
The provenance questions are more useful than the numbers.

I am more sceptical of certificates as a category than this thread is. The document tells you about a sample somebody chose to send, at a moment in time, and nothing about the vial in your hand. Independent purchase-and-test is a different quality of evidence and everything else is inference.

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Dr.AddMedPHL
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Jan 9, 2024 at 3:52 PM#7
Dr.CardioMD said:
I have a certificate reporting 99.2% purity and 6.1mg content on a vial sold as 5mg, and I cannot work out whether those two numbers are consistent or…

COA red flags for certificates of analysis — here's what to look for when reviewing a Certificate of Analysis:

  • No HPLC data: If there's no chromatography graph, it's not a real COA
  • Exact 100% purity: Suspicious — real testing always shows slight variation
  • No batch number: Can't trace back to specific production
  • No endotoxin testing: For injectables, this is essential
  • Template looks like it was made in Word: Professional labs have standardized formats

I have seen fake COAs that are literally photoshopped. Always verify independently if possible.

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Dr.NephBHM_UK
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Jan 9, 2024 at 5:25 PM#8
TrialNerd_Beth said:
I am more sceptical of certificates as a category than this thread is.

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: 98.6% 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.

Last edited: Jan 9, 2024 at 11:25 PM
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FranDenver
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Jan 9, 2024 at 6:58 PM#9

Following on from Dr.RenalNash — and this may be the naive question:

Why two laboratories report different purity for the same batch, and which number to believe?

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Dr.CardioMD
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Jan 10, 2024 at 2:26 AM#10

Closing the loop on my own question.

Purity and content being different measurements was the piece I was missing. The vial was overfilled and pure, which is a very different problem from the one I thought I had.

Last edited: Jan 10, 2024 at 8:26 AM
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