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ForumsCOA & Analytical TestingHas anyone dealt with are all coas created equal? mine looks different from others i see? Page 5

Has anyone dealt with are all coas created equal? mine looks different from others i see?

Dr.ObesityLA Tue, Dec 17, 2024 at 1:43 PM 25 replies 2,200 viewsPage 5 of 5
RickReta_CO
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Jan 2025
Colorado
Dec 22, 2024 at 5:18 PM#21
DanielChem_CHI said:
My vendor review relevant to certificates of analysis: ordered 4 times from my current compounder.

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: 99.0% purity
Day 14: 98.6% 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.

Last edited: Dec 22, 2024 at 10:18 PM
30 3matt_MKE, Dr.ReproEndo, lucas_SP_BR and 27 others
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AussieAnna
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Jun 2024
Sydney, AU
Dec 23, 2024 at 12:53 PM#22
DanielChem_CHI said:
My vendor review relevant to certificates of analysis: ordered 4 times from my current compounder.

Agreed, with the usual condition: that holds for the average and this board is a collection of individuals. A population claim and a personal prediction are different things and get quoted interchangeably.

31 4HPLC_Greg, LibrarianMeg, bri_stats and 28 others
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nick_newbie
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Jun 2026
Virginia
Online
Dec 24, 2024 at 8:28 AM#23
DanielChem_CHI said:
My vendor review relevant to certificates of analysis: ordered 4 times from my current compounder.

Saving this. It is the first explanation that did not require me to already understand it.

Last edited: Dec 24, 2024 at 11:28 AM
32 5MeganSA_TX, LarryQC_SD, wanda_boise and 29 others
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Sigma-Aldrich — Research-Grade Standards

Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.

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hyun_seoul
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Jul 2024
Seoul, KR
Dec 25, 2024 at 4:04 AM#24

Clinical perspective, offered as context rather than as advice. Worth answering the question that was asked rather than the one behind it. The narrow version usually has an answer; the broad version usually does not, and answering the broad one is how a thread stops being useful.

Last edited: Dec 25, 2024 at 8:04 AM
33 6BariatricNurseD, MASHdoc_SA, GenomicsKate and 30 others
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B12Beth
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Oct 2024
Maryland
Dec 25, 2024 at 11:40 PM#25
hyun_seoul said:
Worth answering the question that was asked rather than the one behind it.

Mine went the same way, slower. The detail I would add is minor and it is already implied above.

34 7pam_columbus, nick_SD_fit, ben_calgary and 31 others
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