Elemental analysis of whole blood using proton-induced X-ray emmission.
A technique for the analysis of trace elements in whole blood was developed using proton-induced x-ray emission. Samples of 0.1 ml whole blood from humans and mice were dried, weighed, and then ashed in a plasma asher. Targets were prepared by placing drops made from the ash and a 100-ppM Pd solution onto Formvar backings. The samples were irradiated with 2.25-MeV protons, and the x-rays analyzed in a nondispersive x-ray detector. The elements Fe, Cu, Zn, Se, and Rb were detected with a precision of 7, 18, 7, 50, and 19%, respectively, in human whole blood. The precision of the technique was determined by statistical analyses of two different sets of 27 samples. The system was found to be linear for variations in elemental concentration. The accuracy for deterrmination of Zn was found to be within 10% by comparison to atomic absorption spectrometry.
Evaluation of trace-element sensitivities in PIXE analysis of low-temperature-ashed serum samples.
Abstract Trace-element sensitivities in PIXE analysis are evaluated in serum samples prepared with freeze-drying and low-temperature-ashing techniques. The latter target-preparation method yields better detectability limits for all elements. However, the gain in sensitivity, which is at the most 60% for low-Z elements, is not considered large enough to warrant the use of dry-ashing procedures in PIXE batch-analysis situations as is usually the case in biomedical work.
The determination of sulphur in fluorocarbon polymers by neutron activation
Abstract Sulphur can be determined in fluorocarbon polymers and other fluorine compounds by neutron irradiation to convert sulphur-32 to phosphorus-32 by the (n,p) reaction. The phosphorus produced is determined by a substoichiometric extraction of vanadomolybdophosphoric acid, followed by measurement of β-emission. The method is satisfactory for sub-milligram quantities of sulphur irradiated for only 8 h.