4 Replies Latest reply on Mar 14, 2018 10:15 AM by james_jenkins

    How do you shutdown one ECD on dual GC

    haber

      I have a 7890A with two ECD detector. What is the recommended way of shutting down one of the two ECD. I am asking because I suspect the front ECDs have a problem. Since I have samples to run ASAP, I want to run the back ECD without damaging the front ECD, hence my question. Can I shutdown the front ECD in such a way to avoid any potential damage from running samples on the back ECD?

        • Re: How do you shutdown one ECD on dual GC
          james_jenkins

          Hi haber,

          Typically this is usually an easy method change. Based on the description that you presented, I do have some questions. Is this one column split to two detectors? Or two separate injection port, columns to two detectors. ? A little more on the GC configuration would help.

           

          Regards

          James

            • Re: How do you shutdown one ECD on dual GC
              haber

              Hi James, thanks for your reply,

              I have turned off the heater and signal in the past. This time the front ECD signal is rising at room temperature (see my most recent post) and am worried about damage due to the oven temperature running several times.

              We have two separate GCs: two injector ports, two columns two ECD. basically a front and back GC instruments. I can choose to run one of them or two in a dual mode.

                • Re: How do you shutdown one ECD on dual GC
                  james_jenkins

                  Hi Haber,

                  In this case I would leave the ecd that you are not using hot with proper flow and choose to not collect the signal. In your other post you mention the ECD's are 10 years or more. The signal seems acceptable for the age of the ecds. I have found if the detector is hot with appropriate support gases for column and detector, then the detector will be at its most stable. If you choose to cool it down , then the oven and column will show an effect on the signal. Also anything like siloxanes bleeding from the column will not pass through a cool detector. I hope this helps.

                  James

              • Re: How do you shutdown one ECD on dual GC
                james_jenkins

                Hi Haber,

                Were you able to resolve the issue, if not, feel free to post again.

                James