Topic summary

Particulates in a reconstituted solution: identifying the likely source

Analytics › Impurities & related substances counter-ion content data table HPLC water content endotoxin testing

This is a generated summary. It shows the 5 most-liked posts from a topic of 20, 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.

sourced_claimsTL3Regular5 Aug 2025#1

Posting this under the heading it deserves: Particulates in a reconstituted solution: identifying the likely source Everything below is what sits behind that.

Something about particulates 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.

20 likes 12mo

n.ekstromTL2Regular15 Aug 2025#2

Right — I had this wrong and I am glad to have read it before it mattered.

23 likes 11mo

a.kravchenkoTL223 Sep 2025#9

Post #8 answers the question as asked. The question underneath it is different.

I would rather this thread reach "we do not know" about particulates than reach a confident answer that nobody can support when asked.

22 likes 10mo

w.verhoevenTL212 Oct 2025#13

Trying to state the particulates position in a way that someone who disagrees would recognise as fair, because I do not think the version in this thread passes that test.

19 likes 10mo

DKwiatkowskiTL3Regular24 Oct 2025#16

g.tamm, post #11: Truncation products: fragments from incomplete synthesis or from degradation. They elute quite differently from the intact peptide because they are much smaller and have different hydrophobicity. They are usually well separated. I would not lead a decision with this, but I would not ignore it either. Go to post

Particulates sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable side, narrowly.

27 likes in reply to #11 9mo

Read the full topic (20 posts)

Suggested topics

Topic	Participants	Replies	Views	Activity
Follow-up: Attributing a new peak: degradation product or excipient? Analytics › Impurities & related substances water content HPLC forced degradation endotoxin testing Solved Attributing a new peak: degradation product or excipient? I have a specific reason for asking rather than idle curiosity, and the context is below. A follow-up question about Attributing a new peak that I did…	+15	19	671	17mo
Endotoxin and why it is a separate question from purity — what changed since Analytics › Impurities & related substances HPLC endotoxin testing data table forced degradation On the subject in the title: Endotoxin and why it is a separate question from purity — what changed since Working notes rather than a conclusion. What changes if the standard account of Endotoxin is wrong? I…	+78	91	1k	10h
About the Impurities & related substances category Analytics › Impurities & related substances forced degradation counter-ion content water content Pinned Wiki Deletion sequences, oxidation, deamidation, aggregates, residual solvents, and counter-ion content. This post is a community wiki: any member at trust level 3 or above can edit it, and every edit is recorded…	+6	10	50k	15h
Attributing a new peak: degradation product or excipient? Analytics › Impurities & related substances counter-ion content HPLC data table forced degradation Solved Closed Asking directly, because I could not find a straight answer: Attributing a new peak: degradation product or excipient? A narrow question about attributing a new peak, deliberately narrow, because the broad…		2	15k	18mo
Impurity thresholds: where the common numbers come from Analytics › Impurities & related substances water content data table forced degradation counter-ion content Impurity thresholds: where the common numbers come from — setting out what I have, and where I think it stops being reliable. I have spent a fortnight trying to pin impurity thresholds down and I want to set…	+11	15	825	2d

Related topics — sharing the tags counter-ion content, data table, HPLC

Topic	Participants	Replies	Views	Activity
Coming back to: Deconvolution of a multiply charged envelope Analytics › Mass spectrometry counter-ion content charge states high-resolution MS On the subject in the title: Deconvolution of a multiply charged envelope Working notes rather than a conclusion. Working through the identity arithmetic and I would like it checked. tirzepatide has a…		2	12k	22mo
Counter-ion content and its effect on measured mass Analytics › Mass spectrometry high-resolution MS charge states MALDI-TOF LC-MS Solved On the subject in the title: Counter-ion content and its effect on measured mass Working notes rather than a conclusion. Something about counter-ion content does not reconcile and I would like a second pair…	+100	108	45k	12mo
What a reversed-phase purity number actually is — the long version Analytics › HPLC & UHPLC gradient method system suitability HPLC UV & DAD detection Solved What a reversed-phase purity number actually is — the long version I have a specific reason for asking rather than idle curiosity, and the context is below. I would like to understand what this number means…		2	15k	8mo
A 40-week log with the measurement method stated Outcomes › Progress reports DXA long read data table On the subject in the title: A 40-week log with the measurement method stated Working notes rather than a conclusion. Asking about 40-week log directly, because I have read four threads on it and each…	+87	97	18k	9mo
[2026 update] Waist circumference technique and its repeatability Outcomes › Progress reports DXA long read effect size data table Posting this under the heading it deserves: Waist circumference technique and its repeatability Everything below is what sits behind that. An honest uncertainty about Waist circumference technique rather than…	+23	27	5.9k	21h