Chromatography Forum

I have always seen a specification on standard curve correlation coefficient as greater than 0.98 for general GMP regulated analyses in a QC laboratory. However, recently our lab received a comment that the correlation coefficient specification must be set to a minimum of 0.99.

Does anyone on the board know of a reference on this subject?

Actually it is the same requirement. It’s just that the 0.99 is the correlation coefficient, whereas the 0.98 value is the coefficient of determination, which is calculated as follows: 0.99^2 = 0.98.

Best Regards

Hi

Well now I am a bit confused. FDA (CDER Reviewer Guidance fron Nov-1994) states that r should not be less than 0,999 in most circumstances (r-square not less than 0,998).

Also have a vauge memory (unsure if it from an inspection or formal FDA comment) that FDA at some point stated a r of 0,999 was pretty much expected for HPLC applications.

Hi Kickos,
You’re absolutely right about the FDA recommendations/expectations.
My comment/explanation, however, was authority neutral (i.e. regardless of who expects what). The point is that some people forget to specify the linearity definition when specifying the requirements.
In your example “râ€

[quote="danko"]Hi Kickos,
You’re absolutely right about the FDA recommendations/expectations.
My comment/explanation, however, was authority neutral (i.e. regardless of who expects what). The point is that some people forget to specify the linearity definition when specifying the requirements.
In your example “râ€