Sometimes the question comes up: what should we really test during the PQ on a newly purchased analytical instrument? You did your best so far: URS - DQ - IQ - OQ, what remains to document?
Let's check the definition from USP 1058:
'Performance qualification (PQ) is the documented collection of activities necessary to demonstrate that an instrument consistently performs according to the specifications defined by the user, and is appropriate for the intended use.'
In other words: start to use the instrument already! :)
OK, it's not that simple, but almost.
PQ part 1 - before go-live
Before going out and using the instrument as we should, let's have a formal inventory of the prerequisites we need.
All necessary procedures, user manuals to operate the instrument
All necessary procedures and instruction to administer the instrument
All mandatory trainings on the above
Approved OQ report
PQ part 2 - after go-live
After checking everything you need, you want to make sure the instrument works properly. How can you do this? You perform your first analysis, and look closely if everything goes well.
What are the steps to evaluate?
Switch-on / login to the instrument (or supporting PC)
Create or load the method to use
Perform the analysis with collecting the generated data (you eventually need some sample preparation to carry out this step)
Process the collected data
Compile and sign-off the report (either electronically, or on paper, following your SOP)
Review the report
If you define a periodic check for the instrument, you can use that for the PQ execution, as well.
Let's see some examples what the PQ can be.
The daily check described in USP is ideal for PQ execution, you don't even need additional testing. However, if your pH-meter is connected to LIMS, and LIMS doesn't handle your daily checks, only the test results, you want to test that data transfer in the fram of the PQ, as well.
The situation is roughly the same as for the pH-meter: if your instrument fulfills all daily chek requirements, you won. Again, consider LIMS as a final stop for your data.
LC (and GC, GC/MS etc.)
This is where I'd like to stop for a moment: there might be a need for some requalification when you do some minor change with your instrument: firmware update or relocation of the instrument (but without leaving the server), or a driver update on the application server. But what kind of requalification do you exactly need? The answer here is: PQ!
And this is the place where there is a trap: you don't want to connect the conformity of your PQ with your success on any SST or test result. So what I would suggest is to inject only once (at least in the frames of your PQ), and evaluate the process steps listed above. You can also do this as a first injection of a test sequence, but you only want to focus on the first injection-processing-reporting.