The EPMA analysis for CHIME dating requires standard materials, which include nuclear fuel materials that are rare and sensitive to handle. Any laboratory that does not meet these standards has had difficulties adopting the CHIME dating method. We have developed a working standard technique for CHIME dating to prepare standard materials without use of nuclear fuel materials. Mineral samples, such as small pieces of monazite that are homogeneous in X-ray intensities, are calibrated using well-characterized primary standards in one laboratory. Once this procedure is done, they can be readily usable as working standards in the other laboratories, only with measurement of X-ray intensities. This method is applicable in preparing standard materials for both chemical compositions and determination of X-ray interference correction factors, and it is independent from chemical composition of mineral standard.