Automating Plate Counts

<p>Is there a way to code a plate count cell in Empower so I don't have to keep doing it manually?  We run a one-peak system suitability run every day and use the 1/2 height method for determining Plate counts (N= 5.54* (Retention / (Difference between retention times at half peak height)).  I've tried creating a HalfHeight cell and then a Retention time[HalfHeight] cell but as expected, that does not work.  Any ideas?</p>


  • Hi,

    That looks like the EP Plate Count calculation to me (assuming you meant to square the retention time divided by the retention time difference at 50% peak height) - it's available as a standard column in Empower 2 with the System Suitability option installed (see attached). Not sure I understand what you mean by a cell, but it sounds as though you're trying to use a custom field. If so, could you post a more complete description of the field? I'd like to help, but I don't know a lot about Empower 1 and what options (or columns) you have...



  • We use Empower 2 but do not have System suitability installed.  I attempted to create a custom field that would do the same thing.  However, I'm having difficulty finding the correct functions in order to do that.  I tried to create a field that would take the retention times at half height of a peak, but I think the retention time function is designed to be linked to a peak not an area.  Any thoughts?

  • Think you're right about Retention Time - I've used it as [<peak name>]Retention Time in the past...

    Have been too busy to play in the last few days, but I'll drop in a reply if I come up with anything. Won't be around next week, so hope someone else volunteers to help!

    I'm assuming you don't have the "width@NN" columns available, as I suspect they're part of the System Suitability option too.

    Do you have to use the EP calculation specifically, or is this non-regulated information?