ANALYSIS OF TRACE ELEMENTS IN SOLID AND LIQUID FOODS BY PULSED UV PHOTOLYSIS/PIXE/XRF

摘要

A new analytical method based upon the combination of Pulsed UV (PUV) photolysis and detection of elements via X-ray fluorescence (PIXE and XRF) techniques has been developed and shown capable of rapid and reproducible trace element analyses with increased sensitivity in solid and liquid foods. Pulsed UV-induced photolysis allows for a rapid, acid-free digestion of food samples. Thin or thick samples are then prepared for analyses with X-Ray Fluorescence methods (PIXE and XRF). The combined method was optimized for analysis of Co, Cr, Cu, Fe, Pb, Tl, Bi and Zn, and validated with NIST food standards. The analytical sensitivity of the PUV/PIXE/XRF method allows the study of selected sections of fruits and vegetables, a database useful in determining the uptake, transport mechanisms, and the distribution of trace elements in fresh produce. When applied to edible parts, the analytical results shall also provide valuable information to ascertain potential human health risks due to the presence and bioaccumulation of toxic elements in foods. Practical applications include field studies for analyses of fresh produce as well as for evaluating environmental impact derived from current agricultural practices. Chemical profiling of agricultural crops and soils for improved management and increased productivity using the precision agriculture approach is also being explored.