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ForumsCOA & Analytical TestingMass spectrometry for peptide identity verification — March 2026 Page 6

Mass spectrometry for peptide identity verification — March 2026

TirzTom Fri, Jan 9, 2026 at 3:52 PM 40 replies 1,536 viewsPage 6 of 8
SaraMom3
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Jan 31, 2026 at 5:07 PM#26
PeptideSynthNJ said:
If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way.

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. The objection nobody has made: this only works if the measurement is doing what we assume it is doing, and that assumption has not been tested here.

13 11BethLabQueen, ChrisMacros, KetoKyle and 10 others
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Dr.ObesityMed
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Feb 3, 2026 at 11:04 AM#27
PeptideSynthNJ said:
If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way.

True, and it depends on a baseline nobody has stated. Without knowing where someone started, the same number can be an excellent result or a disappointing one.

That is the short version; the long version is somebody else's post.

Last edited: Feb 3, 2026 at 5:04 PM
14 12PharmacoVig_BOS, SurmountFan_IN, PeptideChemSF and 11 others
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PharmD_Rodriguez
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Feb 6, 2026 at 4:59 AM#28
PeptideSynthNJ said:
If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way.

That reframing is the part I needed.

Last edited: Feb 6, 2026 at 9:59 AM
15 13robert_kc, dan_philly, MeganSA_TX and 12 others
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julia.endo
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Feb 8, 2026 at 10:53 PM#29

From the other side of the consultation, briefly. Order of operations matters more than any single choice here: establish a baseline, change one thing, wait long enough for it to express itself, then measure again under the same conditions.

Last edited: Feb 9, 2026 at 4:53 AM
16 14jason_sac26, chris_chi24, tampaLisa73 and 13 others
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TirzTom
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Feb 11, 2026 at 4:45 PM#30

OP back with an update, since a thread like this is useless without one.

Update: I got the sleep and the intake sorted before deciding it was the drug, and most of the flatness went with them. Not all of it, and I am watching the rest.

38 11DeniseRN_TPA, SandraNC_45, Dr.EndoIndy and 35 others
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