Patent ID: 8433035

Claim:
An X-ray fluorescence analyzing method which comprises: with primary X-rays irradiating a liquid sample containing, as principal components, hydrogen and at least one element selected from the group consisting of carbon, oxygen and nitrogen; utilizing, as an internal standard line, scattered X-rays caused by continuous X-rays included in the primary X-rays for a scattered X-rays internal standard method; measuring the intensity of fluorescent X-rays, emitted from each of elements contained in the liquid sample and having the atomic number ranging from 9 to 20, and the intensity of scattered X-rays from the liquid sample caused by continuous X-rays in the primary X-rays and utilized as the internal standard line; and calculating the concentration of each of the elements in the liquid sample, based on the ratio between the measured intensity of the fluorescent X-rays, emitted from each of the elements, and the measured intensity of the scattered X-rays caused by the continuous X-rays in the primary X-rays and utilized as the internal standard line; wherein the wavelength of the scattered X-rays caused by the continuous X-rays in the primary X-rays and utilized as the internal standard line is so chosen as to be shorter than the wavelength of the fluorescent X-rays emitted from each of the elements and is so set that the measured intensity of the scattered X-rays, caused by the continuous X-rays in the primary X-rays and utilized as the internal standard line, and the mass absorption coefficient thereof are inversely proportional to each other within the range of variation of a composition of the liquid sample, assuming that the sample has an infinite thickness.