X-ray Spectrographic Microanalysis of Human Urine for Arsenic

Abstract

A rapid, precise, and interference-free x-ray spectrographic procedure for the determination of arsenic in human body fluids and tissues has been devised. The organic material in the sample is oxidized, and the arsenic is released by a simplified rapid wet-washing technique using nitric-sulfuric-perchloric acids. The arsenic in the digestion mixture is converted to arsine and collected quantitatively on a silver nitrate-impregnated filter paper disk using a new and convenient sub-micro modification of the Gutzeit arsine generator. The arsenic in the test paper is rapidly and nondestructively quantitated to the nearest 0.1 µg in the x-ray spectrograph. The method is relatively free of the interferences usually associated with Gutzeit and colorimetric techniques for arsenic. The precision of the method is indicated by the fact that 5 µg of arsenic can be quantitated with a relative standard deviation of 2.5% or less. Normal levels of arsenic in human urine have been redetermined.