Topic summary

What a stability-indicating method is and how you demonstrate one — one year on

Analytics › Method validation precision & repeatability system suitability stability-indicating method recovery LOD & LOQ Solved

This is a generated summary. It shows the 9 most-liked posts from a topic of 113, 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.

t.pereiraTL2 Moderator15 Jul 2024#3

h.eriksen, post #2: Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up. 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.

30 likes in reply to #2 2y

c.grimaldiTL2 Moderator Solution21 Jul 2024#5

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

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.

10 likes 2y

IMainwaringTL3Regular4 Sep 2024#27

Transfer between laboratories: a method can be transferred from one lab to another, but the receiving lab needs to demonstrate that they can achieve the same performance. This requires comparative testing and sometimes small method refinements.

27 likes 23mo

c.delgadoTL2 Moderator21 Sep 2024#37

post #36 answers the question as asked. The question underneath it is different.

Range: the concentration range over which the method has been validated. Going outside the validated range is going outside the method's demonstrated performance.

29 likes 22mo

s.okaforTL2 Moderator1 Oct 2024 · edited#43

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.

32 likes 22mo

k.karlsenTL2 Moderator20 Nov 2024#77

post #76 is right about the mechanism and I think understates the practical bit.

Range: the concentration range over which the method has been validated. Going outside the validated range is going outside the method's demonstrated performance.

31 likes 20mo

erratum_fileTL3Regular29 Nov 2024#83

Worth separating two things that post #79 runs together.

26 likes 20mo

journalclub_wrenTL3Regular10 Dec 2024#91

post #90 answers the question as asked. The question underneath it is different.

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.

27 likes 20mo

s.perrinTL2 Moderator27 Dec 2024#104

a.sorensen, post #61: On post #57 — agreed on the reasoning, with one qualification. Two things before anyone answers the substance. First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound. Go to post

Two things before anyone answers the substance.

First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound.

28 likes in reply to #61 19mo

Read the full topic (113 posts)

This topic was referenced in

Specificity, linearity, accuracy, precision, range, robustness — with real criteria — a second datasetAnalytics › Method validation · 58 replies

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