YValue Functionality

I’m wondering if anyone has more information on the YValue function. I’m trying to identify the highest YValue within a range (for example, 15 minutes to 18 minutes) that contains no integrated peaks. I’m fairly certain I can do it, or at least get pretty close, but my solution is very cumbersome, and I’m hoping for something more elegant.

From what I could tell, the YValue function will only accept a numerical value or a reference to retention or migration time. Even though the error message I received (attached) said it would accept X value type peak fields, I tried several with no success. Funny enough, it would allow me to enter CConst or a component custom field reference and save the field but caused the processing server to crash when quantitating data (even when those values were set appropriately). I get “ORA-00942: table or view does not exist” followed by “OCI_Invalid_Handle.”

Any thoughts or suggestions would be appreciated.

Answers

  • I tried to use the Y Value[Retention Time] to capture the highest psi value of a pressure trace which was added as an extra channel during acquisition. Starting with a Peak, Real CF called RT with the formula Y Value[Retention Time] then a Result, Real CF with formula MAX(RT) which gave the max value per chromatogram. Problem is, a pressure trace can be variable and you need a peak to associate with a retention time, whether this peak is sitting neatly on top of the trace or bulging all over the baseline! So depending on the integration settings, you could have a peak just below the max pressure trace picked as the max RT when the real point is not integrated and hence ignored. 

    Can you use the report method to satisfy this? Pick Auto Scaled Chromatogram from the report publisher tree, right click and edit the Scaling tab, under scaling tab pick "Highest Peak" and pick an X Start and End time of what you like, eg 10-13 minutes. Order by Injection ID or whatever you require. You could group an all peaks table with the chromatgram to visually see the list of peaks and which one has the highest Y Value or absorbance by picking MAX in the column properties. 

    If you still need CFs for this, could you try a Peak Real CF such as %.%..MAX(RT*(RANGE(Retention Time,10,15))) and this will return the max value for all injections with a value for retention time between 10 and 15 minutes. 
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