Qualification after adjusting Waters 2695 seal pack

[Terry]

Dear all,

One quick question, after Waters 2695 adjusting seal pack, shall I perform some sort of quantification tests (multiple caffeine solution injection) to demonstrate the adjustment does not have an negative impact on the Waters HPLC?

Regards,

Terry

[tom jupille]

SOP in our lab was that PQ had to be done after *any* service work on the instrument.

[Consumer Products Guy]

SOP in our lab was that PQ had to be done after *any* service work on the instrument.

I'd say that by running System Suitability would demonstrate that your system is suitable !!!! Document the repair and this, of course.

[tom jupille]

I'd say that by running System Suitability would demonstrate that your system is suitable

That's the perennial debate about SS vs. PQ. The thing about SS, though, is that it tests the system *as a whole*, which doesn't necessarily help if you're trying to verify the performance of a particular module, or trying to track down which module is responsible for the problem. PQ provides more "module specific" information. Of course, it's possible for each module to pass but to interact in such a way that the system as a whole fails, so SS and PQ are complementary.

[juddc]

I'd err on the side of a PQ because I've always considered a PQ as an independent test of the system rather than anything related to any one particular assay. You can also compare results with prior PQ runs to see if there are any changes. Typically a PQ takes about an hour to run, so it's no more work than a SS and there is usually a repeatability component to the PQ, so you get SS relevant data as well.

But that's just me...