Topic summary

Validating a method you did not develop

Analytics › Method validation precision & repeatability recovery linearity stability-indicating method system suitability

This is a generated summary. It shows the 5 most-liked posts from a topic of 15, 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.

steady_stateTL3Regular30 Sep 2025#3

c.ramos, post #1: On the subject in the title: Validating a method you did not develop Working notes rather than a conclusion. I would like to understand what this number means before I repeat it anywhere. A VendorInvestigate report on a semaglutide lot gives 99% purity. The supplier certificate for the same lot states 98.5%. Both documents name a… Go to post

Why two laboratories may disagree: after validating the same method, they may still report different purity on the same sample due to integration differences, column age differences, subtle differences in mobile phase pH or temperature. This is normal and not a sign that one is wrong.

20 likes in reply to #1 10mo

b.kowalskiTL2 Moderator7 Jan 2026 · edited#8

n.cabrera, post #6: I read post #4 twice before replying, because I had assumed the opposite. Forced degradation studies: deliberately stress the material with acid, base, oxidant, heat, light to generate degradation products and demonstrate that the method can separate them from the parent peak. Acceptance is that the method is stability-indicating. Go to post

Limits of detection and quantitation: LOD is the lowest concentration that produces a signal above background. LOQ is the lowest concentration at which the method meets precision and accuracy acceptance criteria. Both are determined empirically.

29 likes in reply to #6 7mo

r.laurentTL2 Moderator27 Feb 2026#11

On post #7 — agreed on the reasoning, with one qualification.

Specificity: the method can distinguish the intended compound from related impurities and degradation products. Tested by comparing results on pure compounds, mixtures of compounds, and degraded samples.

10 likes 5mo

mira.patelTL4 Admin15 Apr 2026#14

Staff post. Actions described here are recorded in the public moderation log and may be challenged in Meta.

Precision and repeatability: within-run and between-run variability of the method. Acceptance criterion is typically a relative standard deviation of ≤2% for area measurements.

23 likes 3mo

d.bakkerTL2 Moderator1 May 2026#15

c.boateng, post #13: Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing. The correction was fair and I had been repeating something I had not checked carefully enough. Go to post

Worth separating two things that post #11 runs together.

Accuracy: the method measures what you intend to measure. For purity methods, this is tested by spike-and-recover experiments: add a known amount of impurity to a sample and measure whether you recover the added amount.

16 likes in reply to #13 3mo

Read the full topic (15 posts)

This topic was referenced in

An inter-laboratory comparison on one lot, tabulatedAnalytics › Method validation · 3 replies
Validating a method you did not develop — does this still hold?Analytics › Method validation · 148 replies

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