Evaluation of a new X-ray fluorescent analysis technique for the creation of a Nordic hair database: elemental distributions within the root and the virgin segment of hair fibers.

A new, non-destructive X-ray fluorescence technique for quantitative estimation of elemental content in biological tissues has been developed. Technical and instrumental characteristics of the ITRAX X-ray spectrometer have been evaluated in relation to the properties of biological samples, i.e., human hair fibers. Thus, attenuation variations of the fluorescent X-rays in the hair bulk mass were demonstrated by analysis of sulfur, calcium, and zinc in a virgin part near the root of one hair fiber with elliptical cross section. By rotation of the hair fiber and successive analyses made of the same part of the hair fiber, the results showed that concentrations of elements varied as functions of the diameter of the analyzed hair volume. Other sources of errors are also discussed. The ITRAX instrument allows for precise, fast, non-destructive, simultaneous, quantitative recording of the detected elements and trace elements down to levels of 1 ppm (microg/g). It was used for assessment of normal values of physiologically important elements present in hair in a cohort of normal, healthy Swedish, Caucasian individuals. The database constructed from data retrieved from a conceivably homogeneous ethnic set of individuals represents, to our knowledge, the first of its kind.