Design,Construction,and Application of Xrf Systems for Analysis of Trace Elements in Clinical,Biological,and Environmental Samples. Progress Report,August 1, 1975--June 30, 1976.

摘要

A separation technique has been developed allowing preparation of fixed volumes of rbc's and plasma. Replicate sampling shows rbc and plasma specimen weights of 43 +- 1.4mg and 36 +- 1.9mg,eliminating large background variation due to weight differences of whole blood specimens. An improved specimen geometry has significantly increased the signal to background ratio for low Z elements and with the separation technique,allows quantitative determination with good precision,of changes in the levels of Cl, K,Ca,Fe,Cu,Zn and Br,and in the intra/extra cellular ratios of these elements. Pb is detectable at ''normal''levels (20mu g percent),depending on hematocrit with a one-minute count using 3sigma confidence. Measurements of primate blood indicate a possible rise in bromine level with pregnancy in baboons. In preparation for use in proton-accelerator room, a wheel-based,rack-mount has been constructed which allows transportation of the XRF system for on-site and off-site analyses. (ERA citation 02:011212)