Chromatography Forum

It's been a while since I've come around because my current position is a bit different from those past. I'm doing more product development / R&D / synthesis than I have in years past and LC is only a relatively minor fraction of what I do now. Anyhow, for the past year I've been running an old Waters Alliance system (typical 2695 / 2996) that was purchased at auction in very fine condition. I set the old lady up and found that she had been stored properly, ran perfectly & she passed all OQ / PQ tests, so I set about developing methods and gathering data as needed.

Over the course of the past year, nothing has changed despite much use. The old lady still runs fine (I'm pretty careful with my instrumentation). Note that exactly none of this is in a regulated environment and the instrument is not used for product release.

So, with the exception of the detector lamp, the instrument is as she was when last PM'd in July 2012.

Have a look at the photo taken a few minutes ago and let me know if you'd rebuild. (I have the parts and expertise but if it ain't broke...)

Why rebuild it when it runs good. Only perform PM if you need it due to QA and regulated work. If you don't use it that much.
You can always setup your own PQ test.
And i don't think you have a contract, so you are your own boss.

If you're fine with the performance then be happy

A full rebuild is maybe not nescessary but I would look at these parts:
- needle wash frit: not a big deal to change. Depending on how dirty your samples are.
- check the piston in the injector-needle. If you frequently observe a bubble inside the syringe, then it may be worn out. Can easily check manually during a purge.inj cycle
- on the <Diag> screen check the difference between system and sample pressure. if they differ quite a bit (lets say >100psi) then maybe check/replace the inline filter after the purge valve.
- on the same page, have also a look at the C/D ratio. In isocratic condition normal values are around 1.5
- also do the injector compression check regularly