Compounds quantitating at zero instead of expected concentrations - MH Quant 10.2 in Environmental mode

Hello kdrummond ,

From your cal curve plot it appears you are using ISTDs. That means you need to compare the relative response ratio of your samples to your standards. You can use the columns for ISTD Conc. Ratio and the Relative Response, RR, for a better understanding of your results. See this discussion for some more details about reviewing data for ISTD methods. 

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I see that for the compounds that are quantitating zero, the ratios under column ISTD Conc. Ratio are at 0.0.  In the original iCAL for this concentration level, the ratios are 0.1.  None are 0.0.  Could this be an issue of ISTD concentration?  Or strength of analyte signal?  Thanks for the response.  

Hello kdrummond ,

I suspect that you need to increase the number of decimal places if your ISTD Conc. Ratio is showing 0.0. It may be something very low like 0.025, but I'm not certain how this could ever be zero unless both your standard or ISTD conc is entered as 0. 

This can be changed in the Tools->Numbers Formats menu. ISTD Conc. Ratio is in the Catagory: RSD Ratio, about half way through the list.

Thank you, Howard.  Seeing these extra decimal places has been a good piece of data for batch review.