ApexTrack Touchdown % parameter in Empower Software

Hello-The Empower software ApexTrack processing method Touchdown % parameter controls the placement of peak's baseline end times. The current default value for this parameter is 0.5%. This default value was chosen due to the fact that many peaks tail, and in such cases, a setting of 0.5% will prevent the peak end time from occurring too late. However, for peaks with less tailing, a Touchdown % of 0.5 may cause the peak end time to occur too early.Waters would like to get your input as to whether or not you feel this default setting is appropriate or whether you would prefer that it is lowered, perhaps to a value of 0.05.If implemented, this change would take place in a future version of Empower software and would not impact existing ApexTrack processing methods-the Touchdown % value would remain unchanged in existing methods. If this change were made, only new ApexTrack processing methods would use the new default Touchdown % value. Of course, this value can be set as desired, just as you can do in the current version of software.When considering this, please think about what value would work best for the majority of your data, knowing that a single value will never be appropriate for all types of data. Also consider the impact to you if Waters were to make this change-would this affect any of your SOPs? Are you used to the current default setting and hence a change to this setting may represent a change in your workflow? Would a change have a positive, negative or neutral impact to you?Your thoughts and feedback are very much appreciated. Lauren WoodInformatics Product Manager, Waters


  • Lauren,

    In many cases we find that a setting in the range of 0.05-0.1 works better as a starting point than the default 0.5. This would be a welcome change.

    Thanks for asking,

    Kevin Kolodsick

    Consultant Chemist

    Analytical Sciences R&D

    Eli Lilly and Company

  • Lauren,

    A survey amongst ourselves reached a consensus of 0.00. We usually start from there and work our way up.

    Tony Pecora

    Pfizer Consumer Healthcare

  • Hi Lauren,

    I always start with a touchdown percent of 0.1% and this seems to work pretty well for most of our methods so anything in the region of 0.05 - 0.1% would be a welcome change I think also.

  • I also start low and work my way up. If I have one particularly troublesome peak, I'll leave the %TD high and bump up the PW for the odd peak if it comes out too narrow w/ the PW used elsewhere.

  • Lauren,

    In our laboratory, we always start with a setting of 0.05 % and in many cases it is still too high.

    Damien Brunner

    BASF Pharma

  • As you are talking about future versions of Empower, could it be an option set during project initiation?  Maybe where you allow Apex tracking or not, also have a default value for touchdown and liftoff?  You should know about what to expect for existing methods.

  • I agree that it would be nice for each installation to be able to set their own default value, either in the System Policy/Data Processing Policies where you choose the default integration technique, or as part of the New Project wizard, or both.

    Also - thanks for soliciting input from the community!

  • We typically use values from 0.05 to 0.01.  Defaulting the value to 0.000 would be consistent with the % Liftoff default value.  I suggest defaulting it to 0.000.

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