7 Replies Latest reply on May 16, 2018 2:33 PM by mquintero

    Problem with retention time looking

    mquintero

      Please somebody can help me. I did the procedure for retention time looking in a previous essay with a short method and following all instructions according to the document in the link below. But when I tried to repeat with the target method that takes 65 minutes, The RTL doesn´t work and never appear the message box " Here is where acquisition will automatically collect the 5 RTL Cal Runs"  that appears displays the RTL Cal times. Click OK.

       

      Somebody can help!!!

       

      Thanks in advance

       

      https://www.agilent.com/cs/library/usermanuals/public/G1701-90115%20Getting%20Started_EN.pdf

        • Re: Problem with retention time looking
          valentinrusu

          Hi mquintero, it's possible your target method was previously RT-locked. In either case, please post the exact software and revision you are using. In the software, if you click Help > About, it will show both pieces of information. Please reply with that so that further responses are relevant to your situation. Please also post the model numbers of your GC and MSD.

            • Re: Problem with retention time looking
              mquintero

              Thanks Valentinrusu.

               

              We are using MassHunter GC/MS B.07.05.2479 23-Aug-2016.

               

              Regards

                • Re: Problem with retention time looking
                  ryoboyle

                  Would you mind providing information on the hardware you are controlling with MassHunter? Specifically, what model GC, MS, and sampler are you using?

                    • Re: Problem with retention time looking
                      mquintero

                      Ryoboyle, Thank you.

                       

                      GC Agilent 6890

                      MS 5973N

                      In both methods, the first essay that took 10 minutes and the long method  (60 minutes),  we used DMSO,  the first run when we run the long method, the retention time for this compound was 34,5  minutes and in the 5 RTL Run was 31,3 minutes.

                       

                      Thank you in advance and best regards.

                        • Re: Problem with retention time looking
                          ryoboyle

                          Sorry for the delay.

                           

                          Just to clarify,  you are not seeing a pop-up with the following dialogue: “This action will collect 5 data files with varying pressures. Continue?” when you go to set up a Retention Time Locked method by going to Method > Acquire RTLock Calibration Data as specified in step 2 in the RTLock instructions from the manual you attached in your original post?

                           

                          Do you see any of the other pop-windows where you specify masses for RTL identification or the flows for the 5 calibration runs?

                           

                          Also, what model sampler are you using?

                            • Re: Problem with retention time looking
                              ryoboyle

                              Hello,

                               

                              I just wanted to follow-up to see if you still needed any help setting up your RTL Method. If so, please answer the questions in my previous reply and we can go from there.

                                • Re: Problem with retention time looking
                                  mquintero

                                  Hello  Ryoboyle,

                                  Sorry for the delay in my response.  We got the solution for this problem.

                                  The gas flow in our method is runned at  2.0 ml/s because our system is a GC /MS/ olfactometer and the column finished with a splitter device. The total run time takes 65 minutes per sample.

                                  The RTL method permitted only 4 runs because in the fifth run of the RTL method the pressure in the system fell and the RTL assay didn´t finish. 

                                  The solution was to open more the cylinder regulator, increasing the pressure in the gas line.

                                   

                                   

                                  Thank you for your interest and help.