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Chemstations

Posted: Fri Jan 13, 2006 6:40 pm
by wmilec
I have an 1100 Series HPLC equipt with the ESI source. Eventually I would love to use the hyphenated techinique, but for now I would like to master the HPLC. I would like to set up a gradient and a sequence but I am have no luck with either. When I set up a gradient the base line has a substantial increase at the point I increase the MeOH from 85% to 100% (water is my other mobile phase). As for the sequence set up. I think I am setting it up right but then it doesn't continuously the method I thought I proposed. The chemstations manual is nearly useless could someone out there help me. Thanks !!!!!!!!!!!

Posted: Mon Jan 16, 2006 11:53 am
by Tim
YOur gradient could just be because you are measuring at a wavelength below the cutoff for your Methanol. If you must use that wavelength, try the method using a different organic modifier (e.g. MeCN).

As for the sequence not continuing, check a couple of things. First check that in your ChemStation method you have specified a stop time in the pump module and that all the other modules either say "As Pump" or have a specified stop time.

Second is to check that you have no other analgoue devices attached to the remote line of the HPLC - these could be preventing the HPLC from going back into a Ready state after the run has completed and so the next injection won't start.