About the limit of detection in X-ray fluorescence analysis

Blank experiment in X-ray fluorescence analysis is actually a measurement of the background at the analytical line of an element to be determined. Numerous factors affecting the appearance and registration of the background signal are responsible for its normal distribution. In this work, the possibility of using real samples with low analyte concentrations as blank samples is substantiated. A criterion for the assessment of the correctness of different equations for calculating the limit of detection is proposed. An expression for the calculation of the limit of detection using a one-sided confidence interval of the distribution of analytical signal is derived. An algorithm for the assessment of the limit of detection is proposed.