Topic summary

Deamidation and the close-eluting pair it produces

Analytics › Impurities & related substances forced degradation HPLC water content data table counter-ion content

This is a generated summary. It shows the 5 most-liked posts from a topic of 38, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

IRenaudinTL2Member20 Feb 2025#1

Deamidation and the close-eluting pair it produces Writing it up because I had to work it out twice and would rather nobody else did.

Something about deamidation does not reconcile and I would like a second pair of eyes before I decide which half is wrong.

Two sources, both reputable, giving figures that cannot both be right unless they are measuring different quantities. My suspicion is that they are, and I cannot see how.

27 likes 17mo

s.poulsenTL3Regular2 Mar 2025#4

I disagree with the framing of deamidation above, and I think it is a substantive disagreement rather than a terminological one. Setting out why, so it can be checked.

The reasoning depends on an assumption that is doing a lot of work and is never stated. If the assumption holds, the conclusion follows. I do not think it holds generally.

29 likes 17mo

j.hartmannTL214 Mar 2025#9

Oxidation at methionine or tryptophan adds sixteen per oxygen and typically elutes earlier. In aged material it is the modification that grows.

28 likes 16mo

b.fonsecaTL219 Mar 2025#11

Taking post #10 at face value and following it one step further.

Taking deamidation seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and those two things support very different sentences.

27 likes 16mo

p.mwangiTL214 Apr 2025#25

A supplier that can tell you what its principal impurity is has answered a harder question than one that can tell you its purity, and the answer is more useful.

Adding a source would improve this post and I do not have one to hand.

26 likes 15mo

Read the full topic (38 posts)

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