Is there any difference between Channel ID, Injection ID and Date Acquired when ordering reports?

I run a standard followed by 30 samples and the standard is injected 5 times over the course of the run, The standard is in the same vial so after each 6 samples the first vial is injected again. I want a table in my report that calculates the RSD of these 5 standard injections, I know I could just filter by Sample Type of Standard and group by peak name but if I picked channel ID or injection ID or Date Acquired (all ascending) as "Order By" parameters is there any real difference between these 3?

Channel ID will always order in order of channel injected presumably so if I have an injection of a sample with two actives, one at channel 220nm the other 230nm, then I would first get the peak area of active in 220nm in the first injection followed by the peak area of active in 230nm in the first injection followed by the peak area of active in 220nm in the second injection and so on...

Date Acquired would I presume give you a whole mishmash of areas only ordered by time of injection and no filter for the channel unless you specified it. Injection ID the same? Is Channel ID the deepest filter you can pick when wanting an order exactly as injected onto the machine? Presuming a one channel species, will an order by channel ID always get you sequential values, even considering several injections from the same vial?

Best Answer

  • Dan_Ramlose
    The real differences between these terms happens when a one-to-many relationship exists (multiple channels per injection). If you're wanting to sort a particular channel type by acquisition time and/or injection ID, you need more than one term to filter and/or order by.

    These ID numbers are not (as far as I know) unique to each Empower database but are unique to a given project.

    To collect standard data first, choose "normal" for processing of standards and "don't process or report" for samples. Your standard results will then come up first and together when you sort by result ID as your samples will generate no result files until you "quantitate U*" at the end of your sample set method.


  • "if I picked channel ID or injection ID or Date Acquired (all ascending) as "Order By" parameters is there any real difference between these 3?"

    No.   Empower assigns the injection ID/Channel ID sequentially upon injection which corresponds to the date acquired.  The only case I can think of where you would need to concern yourself as to which you choose is if you were looking across multiple projects (e.g. global view).

    "Channel ID will always order..." and "Date Acquired..."

    Yes, it should.  I think it goes back to your first paragraph and how you could group by peak name to reduce the likely confusion in this scenario.

    "Is Channel ID the deepest filter..."

    I'm not sure what you mean by deepest filter, but as above, equivalent to injection/date from an ordering perspective.

    "Presuming a one channel..."

    As above, equivalent to injection/date, so it should be sequential by vial as a default as each injection would get a sequentially higher channel ID.
  • In older Empower versions, in large deployments with multiple Citrix servers, there is a slim possibility that injection and channel,IDs may be less reliable compared to Date Acquired for demonstrating exact true injection order. It was due to how IDs were assigned in a Citrx environment, while true date synchronization makes Date Acquired  much more reliable. 
  • @HeatherLongden
    Interesting - I just tripped over an example of a discrepancy between "Injection ID" and "Date Acquired" ordering in a Basic LC Peaks Table. Notable is that this is on a fat client in an enterprise installation without Citrix servers. All of my standards clump together in the table if I order by Inj. ID and the trailing standards show up (correctly) after their sample groups if I order by Date Acquired. As the standards are processed on the fly and samples are processed at the end, my guess is that there is an errant schema in play here (can't blame Citrix in my case).


    PS - Build 3471, SR2 Hotfix 2, options limited to Enterprise Base, GC control, System Suitability, SQT for software, SystemsQT. DB Version
  • Doesn't sound like the Citrix can be blamed.....  but maybe its an odd artifact of buffering? If the Database is not available at acquisition, perhaps the order that IDs are assigned by the DB after recovery is not matching the order they were acquired?  Its just a guess...