Deductive Prediction of Precision in Measurement, Calibration, and Standard Addition Method in Atomic Absorption Spectrometry for Cadmium

The relative standard deviation of measurements in atomic absorption spectrometry for cadmium determination is predicted by the signal fluctuation model, which is made up of the white noise and Markov process. The standard deviation (SD), w̃, of the white noise and SD, m̃, and autocorrelation parameter, ρ, of the Markov process are determined from the power spectrum of the actual signal fluctuation in the system and in turn are put to use for the uncertainty prediction of measurements in the time space. The confidence intervals of the conventional calibration and standard addition method are calculated from the predicted SD of measurements.