Mathematical Assessment of Combined Standard Uncertainty of Measurements in Using Concentration Ratio Calibration in Inductively Coupled Plasma Atomic Emission Spectrometry

The mathematical assessment of effect of uncertainty components on measurement results in using concentration ratio calibration in inductively coupled plasma atomic emission spectrometry was performed. Formulas for the calculation of the relative standard uncertainty for different components were derived. It was shown that, in different scenarios of using concentration ratio calibration, the combined standard uncertainty basically depends on the repeatability of the determination of the intensity ratio of the analytical line of a test element to the line of the main matrix component of the sample.