Calc

Question

Hello, 
 In the technical documentation for ChemStation I have found a section which is of my question 
 
 Please take a look 
 I need a formula to calculate the % in my samples

martin.adams · Accepted Answer

Alex, 
 
 The formula is as shown in the manual below where the RFx is calculated from the calibration and expressed as amount(x)/response(x). I cannot say what that calculation is for your method. It could be a simple average response factor calculation, linear formula, or several others. 
 
 Marty Adams

Andy Wright · Answer

Hi Alex1960 
 Have a look at the next page in the documentation in the section describing ESTD. 
 
 If you include a sample amount in the sequence table and choose ESTD% as the calibration settings section of Specify Report. 
 Chemstation will calculate the mass percentage by taking the measured amount, divided by the sample amount and multiplied by 100. 
 /Andy

Andy Wright · Answer

HI Alex, 
 I see what you're saying now. I think the document should have RF=Amount/Response where this is determined from standards. For each calibration, Chemstation calculates the equation of the line of best fit according to the calibration settings. This equation is then used to calculate the amount of analyte, which is then corrected using multipliers and dilution factors. Since each calibration is unique, I can't provide you with an exact equation. For linear calibrations, the line would have the equation response = a*amount + b, so given a response for a sample, amount can easily be calculated. 
 Does that make more sense? 
 /Andy

Calc

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