Waters Alliance Dissolution-HPLC

[John]

Does anyone have experience with either Hanson or Distek dissolution systems with a Waters HPLC direct autosampler? I'd like to get an idea of the reliability of these systems.

[LC_labrat]

I have never used the direct autosampler. I believe it also uses the Alliance HT HPLC. We bought one several years ago in hope of adding the direct autosampler later. I found the HPLC to be troublesome. It either ran extremely well, or if the extra solvent line, which is constantly running, ever had a problem (ran dry) it would take a long time (several days) to get the system equilibrated again. We finally put on a 10L bottle of solvent.

[John]

What is that extra solvent line for? Why did you not opt for the dissolution autosampler in the end?
J

[LC_labrat]

The Alliance HT has additional wash and purge solvent lines. If I understand it correctly they continously flush the needle/injector, increasing the ability to make faster injections. We went with Varian baths and autosamplers instead. The autosampler uses HPLC vials and we just transfer them over to the LC.