Use of hair as a diagnostic tool: X-ray fluorescence Zn monitoring in hairs of patients under parenteral nutrition

International audienceX-ray fluorescence excited by synchrotron radiation is a very sensitive method, allowing us to analyse trace elements along a single human hair. The results presented here demonstrate the application of the method on patients under parenteral nutrition in order to validate an adequate supplementation of Zn. We were able, by measuring different hair segments distributed along the hair, to monitor the trace element concentration during the therapy. Special care has to be taken for the statistical interpretation of the results. Indeed, the usual techniques applied to human hair analysis yield a mean concentration, whilst the analysis of a single hair revealed important fluctuations in three levels: with time (along the hair), between hairs of one person as well as between hairs of different persons