automatically RT

Hi,

how can i change automatically RT in MH 10.1, for example when i change column and etc. I have more than 100 analytes and i dont want to update each analyte manually. Iam using retention time tool for now.

  • Hello, 

    Are you looking to update the RT in MH Acquistion, Quant, or Qual?

  • You can find the other options to update the RT after loading and editing the method. (Tip: Select a mid- to high-range calibrator before editing the method to use to determine the new RT's.) Once you can see the Method Tasks, there will be an Update menu at the top of the window.

    • Update Retention Times will allow you to choose compounds to update the RT to the current peak's RT at the max height.
    • Update RT from ISTD is helpful if the relative retention times of the target compounds is already in the method. Using this option first sets the ISTD RT to that observed in the selected calibrator and then the target compound is calculated to be ISTD RT x Average RRT.
    • Average Retention Time opens a window, so that you can again choose compounds and specify whether the resulting average RT should be calculated from Cals, QC's and/or weighted Method RT's. 
    • Shift Retention Times again allows you to select the compounds to update by either an absolute time in minutes or a relative shift (a percentage of the RT). For example, if your RT is 2 minutes and you set a relative shift of 90%, the RT would be 1.8 min.

    To complete the list of ways to update the RT in Quant, there is also the Update Retention Time Tool in the Update menu that you mentioned. This is a graphic-based tool that allows the RT to be set by left-clicking on the time you would like to use. This tool will also allow you to move through the compound list in the same window updating RT's based on the peaks found in the window.

  • Thank you for your response, but i know all this. If u want to use those updates u must manually integrate peaks 1st if i'm correct. What I'm looking for is an application or maybe macro where I enter, for example, one analyte and all other RTs are automatically filled in based on some factors. Idk if something like this exist.

  • Ok, in that case,  it sounds like the peaks are outside of the retention time window set up in the Method section, Retention Time Setup. Is that true?

    I do have some more questions that will help determine the available options, since there isn't a tool that works exactly as you described.

    • What type of data are you collecting, e.g. SIM or MRM?
    • Do you have internal standards?
    • How large of a retention time shift are you seeing?
    • How often does this shift occur - every batch, every 10 batches, every month?
  • Yes, we have quite narrow refference and non refference window + delta left and right, and when we change column, like every 2-3 months sometimes less because of dirty samples we have shift 0,3-0,6min. And when we do regular maintainance every 2-3 days shift is not that much, but we are using ISTD with time refference flag and when we update retentions times sometimes shift is greater and  RTs of ISTD is fine but regular analytes are shift because of that time refference flag, to avoid this we must manually integrate those peaks. We are mostly collecting data in SIM few methods are in MRM, i want focus on SIM. We have around 20 instruments so we deal with it every day.

  • Hi PavelK,

    You'll likely need to take more than one step to address the retention time shifts that you're seeing. I would recommend contacting your local Agilent support team (Contact Us | Agilent), so that they can assist with determining a workflow that will work after looking at the data.

  • Hi,

    ok, thank you for your time.

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