New instrument available, Do I need to revalidate my test method?

Hi all!
I have to change my UV spectrophotometer for a new one, actually we are currently running IQ/OQ for the new instrument. I have validated the method using the old instrument since was the only one available, if I change the instrument, Do I need to revalidate the test methods? If so is, to verify Precision will be enough?
Thank for your help.


Hi Tirso,
Precision will be tested during the IOQ phase. As a minimum, you will have to writte an equivalence certificate based on the IOQ of the new and the old one (material certificate and other applicable test… TBD). If the equipement are not identical you will certainly have to revalidate the method or as a minima to confirm it on one run verus ur SOPed specifications.

In general, No. Particularly, because UV methods are a comparative technology, that is many methods use a standard, and use a ratio of the absorbances to determine the analyte’s concentration.

However, there are some methods that use an absolute absorbance and its these that should be closely examined. At a minimum you should do a documented review of all your methods.

Most of test method are compared against a standard (ratio I guess), but not sure what do you mean when you say absolute absorbance, so if I perform a detailed analysis of the difference within the features of the instruments.

There are methods (mostly food methods by the AOAC) that say so much absorbance at a particular wavelength equals so many mg of an analyte. Thus, no ratio. This means that 1 UV spectrophometer is not equal to another spectrophotometer (since it may be more efficient in gathering light).

Thks all for your replys.