[lespaul]

Im planning on purchasing a used HPLC system for food analysis and have narrowed down our options to a HP 1050 or Waters 600 (each w/DAD or VWD). Will mainly be used isocratically.

Would anyone here recommend one over the other in terms of (1) ease of use/user interface (2) replacement parts, etc.

Any feedback would be great.

[Arkcon]

Hmmm...these are both older systems, its hard to really be sure.  However:

For starters you'll have to describe the systems better:  do they come with autoinjectors, or will you syringe inject each sample?  That can get tedious as you try to validate.  What model of Waters autoinjector will you get?

The HP1050 is more of a modular system.  Its meant to go together with other 1050 components, stacked together, with short path-lengths between components.  The Waters 600 system is a big old box, just because you can stack components, doesn't mean they're as "close"as the 1060 system.

Ease of finding parts is a little tricky.  Before you buy either, call both Waters and HP and find out what sort of service plan they offer.  They want to help,once you make some money you may buy their next gen system.  But they may be limited in the help they can give you.

I'm somewhat biased towards Waters software over HP.  Lots of people share this bias.  There's nothing wrong with HP's software, except some of its functions are a little too ... "engineering", when they could be more "push button" as they are on Waters.  Again, I don't know what software you're going to get for these systems either.

[marquis]

Agilent (the new name for HP instruments) discontinued servicing their 1050s some years ago.
You may find a retired service engineer or third party source who has some of them, though.

If you are doing isocratic work, I think the pumps on the waters system are better.  We sure
noticed the difference doing GPC work.  If you go to gradient (or think you may do gradient) work,
I would choose the HP.

Good luck.

[Arkcon]

The Agilent or HP, depending  on when it was built is a little more close to a "modern" system.  Close to being a UPLC.  So you can get better results from it, but it can be unforgiving if you're sloppy.  In other words, you might get sharper peaks and better resolution, but if you leave fluid lines long, you'll get worse results.

Now the Waters 600 system has giant machined steel pump heads.  Built like a a battleship, you can do almost anything.  If you wanted top go semi-prep:  that is, you want to get a fatter column, load more and capture some of what you've analyzed by HPLC for a different analysis, the 600 will lean towards that just fine.  The fluid lines are up to you.  The better you can cut them, the better the resolution you'll get.