Analytics · Method validation

LOD and LOQ: definitions people get wrong

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

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e.iyerTL2 Moderator12 Nov 2025#1

LOD and LOQ: definitions people get wrong — setting out what I have, and where I think it stops being reliable.

A documentation question rather than an analytical one.

I have a certificate in front of me that reports a purity figure, names a technique, gives a wavelength, and stops. No gradient, no column, no injection volume, no chromatogram.

What can I legitimately conclude from that document? My instinct is "almost nothing, but not literally nothing", and I would like to know where the people who read these professionally draw the line.

2 likes 8mo

s.ferreiraTL2 Moderator18 Nov 2025#2

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

0 likes 8mo

c.niemelTL3Regular22 Nov 2025 · edited#3

Worth separating two things that the opening post runs together.

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.

22 likes 8mo

This topic was closed 180 days after the last reply. Closing is automatic for quiet topics so that a settled answer does not collect new questions underneath it. If you have a follow-up, open a new topic and link back to this one — that keeps both readable and gives your question its own title.

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