UOP-389 Calibration Standards

I am currently reviewing the UOP-389 methodology for trace metals in organics by ICP-OES, and the method seems to only use one blank and one standard at 10 mg/kg while promising detection limits between 0.01 and 0.11 mg/kg. The analytes are segregated by minimizing potential interferences between analytes of interest. I am worried that only 1 point of nonzero quantification may not be sufficient to reliably produce results with such low MDLs. 

Has anyone had experience with this method? Would I be wrong to assume that I should make more standards with this methodology to have a more robust calibration? There isn't much literature around this method's use, but it seems to be accepted in my field (renewable fuels) as reliable. Other labs that perform this methodology also seem to minimize the nonzero calibration points, only using 1 or 2 at most.

Any insight into this would be appreciated!

Parents Reply
  • MDL is the method detection limit.

    On the ICPOES software standards tab, there is an option to check "weighted fit" for the calibration curve. Statistically for a general calibration curve without weighted fit, more weight is given to the highest calibration standard on a calibration curve. But with weighted fit, it applies more weight to the lower calibration point(s). This means you have good accuracy on the lower end of the curve and improved accuracy on low concentrations. 

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