||The usual method to determine the relative sensitivity curve for total-reflection X-ray fluorescence (TXRF) uses multielemental solutions, which may be purchased or prepared in the laboratory. In the former case, the accuracy and precision of the concentrations are certified by the provider, while in the latter, the experience of the technical staff determines the analytical quality. These procedures are costly and the quality of the solutions cannot be easily verified. The goal of this work was to use pure crystalline salts containing two elements that may be quantified by TXRF for the calibration of the spectrometer. The analysis of these samples along with a mathematical procedure assures good precision of the results. The reported method is economically efficient, simple, and eliminates the uncertainties of the element concentration in the samples produced by the standard methods, thereby improving the quality of TXRF results.