Interchannel calculations in Empower?

<p>Hi,</p><p></p><p>Is it possible to incorporate data from different channels (say from different detectors) into one custom calculation field? I am aware of the general formula of <em>Label.Injection.Channel.FUNCTION(Statement)</em> or <em>Label.Injection.Channel(Statement)</em> but what it seems to do is just selecting a single channel and discarding all the rest. If I omit the channel specification, then the field values are calculated for all channels and are based on that same channel, which is what I expect, but as soon as I specify a channel the results are calculated only for that channel and the results collected from a different channel are left blank. Is this how this formula is supposed to behave? Is there a way I can do interchannel calculations?</p>

Answers

  • As far as I am aware, this is the intended functionality and everything is bahaving as normal. If you specify a channel in your custom field, then the field only runs on that channel. If you use the "%" wild card for the channel, all channels will be calculated, but results are based relatively to the channel derived.

    I may know where you are going with this though... Let's see if this helps:

    I once had to work with transferring a very old and off assay to a UPLC. The old and odd part about the assay was there was a wavelength change mid run. I believe the run started at 270 nm and half way through it switched to 280 nm. Anyway, some components were detected at 270 nm and others at 280 nm; the same applied to system suitability compounds. So, I needed to come up with intersample calculations for both assay results and system suitability at two different wavelengths.

    My solution was to use a partial wild card for the channel portion of the custom field, which became "2?0nm" for the channel portion of the custom field. In the processing method, I then "tied" components to a specific detector channel as all components could be detected at both wavelengths. The summary report formatting worked in a smilar fashion due to locking down components to a specific detector channel in the processing method.

    I hope that helps you out some...