Microanalysis of solid samples by total-reflection x-ray fluorescence spectrometry

Microgram quantities of different solid powders and smears of alloys were analyzed with total-reflection x-ray fluorescence spectrometry, a special variant of energy-dispersive x-ray fluorescence spectrometry. The samples were analyzed directly without chemical pretreatment. The method works simultaneously for about 20 elements. Quantitative analysis with internal standardization was executed with 10-50 mg of sample mass, but only microgram quantities were necessary for the determination. The dynamic range of the method is about 4 orders of magnitude; detection limits are in the microgram-per-gram region. Results for standard reference materials such as coal fly ash, bovine liver, tomato leaves, and electric furnace dust are reported. Relative standard deviations mostly below 15% are found for the repeatability. Relative deviations from the certified values which characterize the accuracy are of the same order of magnitude