A method has been developed for the simultaneous analysis of phosphorus-32, sulphur-35, and chlorine-36 in urine. The sample must be divided for the analysis; therefore, at least 500 mL of urine is required. Chlorine-36 is estimated by counting AgCl after interferences have been removed by Fe(OH)3, Ca3(PO4)2, and BaSO4 precipitations. Sulphur-35 is estimated as BaSO4 and phosphorus-32 is estimated as BiPO4 after interferences have been removed by cation exchange and coprecipitation. Cross-contamination of the radionuclides is negligible and the chemical recoveries and limits of detection are as follows; Cl-36, 90% (269 mBq); S-35, 95% (144 mBq); P-32, 70% (38 mBq).
During the heights of ancient Egyptian civilization, statues of deities and pharaohs were often constructed of hard and colourful igneous rocks, such as granite and diorite. Most of these statues remain in an excellent state of preservation. However, others have unexpectedly fragmented, in some cases only a few years after having been excavated in near-perfect condition. In the present work it is shown that two interrelated physicochemical processes contribute to this degradation: (1) the infiltration of saline H2O and (2) subsequent alteration of the constituent minerals. Conclusions were reached on the basis of neutron activation and atomic absorption analyses of rock samples from two sites in Upper Egypt and leached soluble salts therefrom. These samples were identified as quartz diorites on the basis of petrographic and X-ray spectroscopic examination. The chemical significance of the geological nature of the stone is discussed. Possible precautions to be observed in the field are presented.
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