U. Majewska et al., Some aspects of statistical distribution of trace element concentrations in biomedical samples, NUCL INST B, 150(1-4), 1999, pp. 254-259
Concentrations of trace elements in biomedical samples were studied using S
-ray fluorescence (XRF), total reflection X-ray fluorescence (TRXRF) and pa
rticle-induced X-ray emission (PINE) methods, Used analytical methods were
compared in terms of their detection limits and applicability for studying
the trace elements in large populations of biomedical samples. In a result,
the XRF and TRXRF methods were selected to be used for the trace element c
oncentration measurements in the urine and woman full-term placenta samples
. The measured trace element concentration distributions were found to be s
trongly asymmetric and described by the logarithmic-normal distribution. Su
ch a distribution is expected for the random sequential process, which real
istically models a level of tract elements in studied biomedical samples. T
he importance and consequences of this finding are discussed, especially in
the context of comparison of the concentration measurements in different p
opulations of biomedical samples. (C) 1999 Elsevier Science B.V. All rights
reserved.