5 Replies Latest reply on Feb 8, 2019 9:07 AM by hebgent

    Can I Continue A Sequence For a Full Day?



      I am using chemstation with intelligent reporting for our 1220 Agilent HPLC. I am going to be running a QC procedure all day long on the HPLC and was wondering if it is possible to keep the same sequence going inevitably (or until the end of the day at least) even if there are no more samples to be injected at any present time. I would just like to be able to add samples, change my sequence table and continue on with the same sequence for a full day. There will likely be short gaps of time where there are no samples left to run in between. I would also want the pump to stop running at full speed during these pauses and only run very slowly until a new sample is ready so as to not waste mobile phase.


      Is this possible to do? And if so, how? Thanks in advanced.

        • Re: Can I Continue A Sequence For a Full Day?



          Sorry for the delay. I do not believe there is a way to indefinitely pause a sequence once all the samples have been completed so that the user can then append more samples to the end of the sequence.


          You might be able to accomplish what you want by using the Queue Planner. Here is a brief tutorial video on the Queue Planner: OpenLAB CDS Chemstation tutorial: Queue Planner . A new feature to OpenLab CDS ChemStation rev C.01.09 which is not discussed in the video is the ability to insert or append custom commands. These commands can be used to shutdown the pump in between sequences if needed.


          Hopefully this helps. 

          • Re: Can I Continue A Sequence For a Full Day?

            Hi gmartinetti01,


            I don't think there is and easy way to do what your asking for but I think there are 2 different ways to kludge something together.  Like ryoboyle suggests the Queue Planner is probably easier (The Partial Sequence option also allows for some interesting sequence control).


            If I understand your question correctly you could make a sequence for your first set of samples then add a (fake) sequence to load a standby (low flow) method or some custom commands and then a pause.  Every time you add samples you would make a new sequence then standby then pause and add them to the Queue Planner.  This should work (I Think).


            The only problem is that every sequence will be in its own container so you'll need to add the separate sequences together and reprocess the sample runs.  I'm assuming you have a custom IR summary report that needs to be generated which is why you wanted to continue a sequence.  When you create a new result set all sample data, method data and reports get grouped together in a new directory.



            • Re: Can I Continue A Sequence For a Full Day?


              I would create a new (isocratic) method that's using a low flow rate and the starting mobile phase composition of your sample method, or the composition of the storage conditions of your column (i.e. 60-40 acetonitrile-water). I would set the run time of the method for a couple of hours, or the time you are expecting the gap between the samples would be. I would create the sequence with your first samples entered and at the end add a blank injection using this long isocratic method. When the first set of your samples are finished, the next injection will be the blank using this long, isocratic method. When you have your next set of samples, simply enter them into the sequence after the "blank" injection, then go to the pump control and just change the run time. Let's say, you set the run time of that method to 120 minutes, and you came back to enter the new samples after 23 minutes. That point I would manually change the run time of the method from 120 minutes to 24 minutes. The isocratic method will stop after 24 minutes and the system will inject your next sample in the sequence. If you are using a gradient method or you set the mobile phase composition of this long isocratic method to the storage conditions, I would inject first at least one blank injection using your "sample" method. Repeat this procedure (sequence samples followed by the blank injection)  until you have all of your samples analyzed. It is not the perfect solution, but I think it can work


              • Re: Can I Continue A Sequence For a Full Day?


                I like to suggest the following solution:

                • set up your stand-by method like suggested by Aniko
                • in addition modify the run time checklist like this:


                (Note: In ChemStation C.01.08 or previous releases you have to type the macro command PauseSequenceBeginning with rev. C.01.09 the Pause Sequence command can be made available to the drop down of the pre-run commands. (Please post a new question if you can't manage to add this command to the pre-run command selection list))

                • Save the method as e.g. PauseSequence.M
                • Use this method as blank run (no vial location specified) at the very end of your sequence table:


                Now, when you run the sequence and it hits the last line, the sequence will pause untill you have appended more runs and resumed the sequence

                Do not forget to copy/paste the blank run to the very end again.


                This way you can generate very large result sets. (Keep in mind that sequence summary reports or uploading such a resutl set to a data back-end may take a long time).


                'hope this helps.