Improving the in vivo X-ray fluorescence (XRF) measurement of renal mercury

In vivo polarised X-ray fluorescence (XRF) measurements of renal mercury ha ve previously been reported (Borjesson J, Barregard L, Sallsten G, Schutz A , Jonson R, Alpsten M, Mattsson S, 1995. In vivo XRF analysis of mercury: t he relation between concentrations in the kidney and the urine. Phys. Med. Biol. 40, 413-426). However, with the detection limit reported therein, thi s system is limited to measurements in cases of significant mercury exposur e. An improvement in detection limit is desirable to produce a tool capable of occupational monitoring in cases of mild to moderate exposure. Therefore, design changes have been investigated to improve system performa nce. Through Monte Carlo simulation and experiment, optimal parameters were determined with respect to polarisation and filtration, as well as the ide al X-ray tube voltage. The optimal configuration will be discussed. A preli minary comparison in terms of minimum detectable limit (MDL) will be made w ith the preceding polarised XRF renal mercury system. (C) 2000 Elsevier Sci ence Ltd. All rights reserved.