Abstract：Certified reference material of dolomite and limestone underwent direct compression, and the contents of calcium oxide, magnesium oxide and silicon dioxide were corrected by loss on ignition, so the calibration curve was plotted based on the correspondence between its content and intensity, and thus the method for the determination of three main components of dolomite and limestone by X-ray fluorescence spectrometry(XRF) was established. One portion of the sample could be determined after direct compression while another portion could be analyzed with the loss on ignition test, so the dosage of the certified reference materials could be significantly reduced. The tests on ignition time showed that when the analyte was burned for 0.5 h at 1 100 ℃, its weight could become constant; and the tests on granularity showed that when the sample size surpassed 200 mesh, the granularity effect could be eliminated. Matrix correction with the CaO and MgO contents could eliminate its influence on low-content SiO2; and the adoption of experiential coefficient method can eliminate the absorption-enhancement effect among the elements. Precision test results indicated that calcium oxide, magnesium oxide and silicon dioxide measurement results had relative standard deviations (n = 8) in the range of 0.03 8 %-3.5 %; certified reference materials of limestone and dolomite as well as actual samples were tested to determine the accuracy of the method, and it was found that the measured values were consistent with the certified values or those obtained by titration method.
