Tutorial: Calibration Curves |
---|
Potentiometric Analysis using the Calibration Curve MethodIn potentiometric analysis, the measured signal increases with the logarithm of the analyte concentration. This functional relationship creates complications when calculating confidence intervals for the analyte concentration. Two of these complications are:
ExampleIn the potentiometric determination of Pb2+ in solution, the following calibration data was collected.
Another solution, whose concentration of Pb2+ was not known, yielded a measured potential of -300.8 mV. Report the concentration of lead in the solution in the form of a confidence interval. Answer: 319 ppm (best point estimate); 243 - 420 ppm (95% CI) |