custom field and unknown peak amount calculation

I need to calculate sample concentration based on the formula,  %v/v= (sample area/ standard area -sample area)x standard concentration/10000. I made a custom field: Area/((S01.%.(Area)-Area))*cconst1/10000. I specified the standard concentration of cconst1 in processing method. This custom field only works for the named peaks which have corresponding standard peaks in the standard. Is there a way to build a custom field that can calculate all the unspecified/unnamed peaks in my sample based on a particular standard peak?  check default peak in processing method doesn't work. 

Answers

  • In the custom field itself, just set it to calculate on all peak types. 

    However, you really do not need a custom field to do this. A combination of standard concentration(s) in either the processing method or sample set in combination with dilution in the sample set will get this result in the default Empower "amount" field. 
  • My CF is set at all sample type and all peak type. Since there is no unknown peak with known value in my standard injections, this CF doesn't work for unknown peaks in my sample injection.  How do I do without CF? I'm using one concentration calibration, no dilution in sample. I think empower does automatic calculation in this formula: Sample Area/Standard Area* Standard Value. My calculation must be Sample Area/(Standard Area- Sample Area)*Standard value.  
  • I think for this to work, you need to point Empower specifically towards your standard peak in the standard labeled as S01. In your processing method, enter this peak in CCalRef1. Make sure default peak is ticked for this peak also. Then your formula becomes  Area/((S01.%.(CCalRef1[Area])-Area))*cconst1/10000.
    There is a chance that this still wont work because the CConst value is tied to the known standard peak and may exclude unknown. In which case, create a Sample, Real custom field with enough precision for these standard concentration values and call it something basic like "Std_Conc". Then put this value in the sample set for all your samples, and alter the formula:  Area/((S01.%.(CCalRef1[Area])-Area))*(Std_Conc/10000). Process a sample set and your values should populate in the result set. 
    One of these scenarios should fix it. 
  • I tried both and both are not working...Also after adding Ccalref1 to the formula and changing the processing method, the known peaks are not being calculated correctly either...