Narrow Results

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.

Trace element analysis via X-Ray Fluorescence (XRF) and Proton-Induced X-Ray Emission (PIXE) techniques were applied to several samples of fresh and processed foods. Thin samples of fresh fruits and vegetables, processed dry foods. and spices were included in these analyses. The results indicate that XRF and/or PIXE analysis is applicable to these types of samples but require special and simple modifications in sample preparation techniques, and the inclusion of new matrix type corrections for data analysis. However, the non-destructive nature, reproducibility, efficiency and high sensitivity that characterize these multi-element analytical procedures can provide new potential methods for detecting trace elements in foods and in many agricultural commodities. Toxic metals such as Hg, Pb. and As were detected in some foods. In addition, other essential or neutral trace elements such as Na, K, Mg, Ca, Cu, Cr, V, Zn, Mo, Fe, Mn, Ni, Se, Cl, S, and P were also detected. These and other elements can be analyzed rapidly and with high sensitivity for applications in process control and for certification of food quality. Developing these techniques and procedures specifically for food and for various agricultural products may provide new analytical options and help mitigate the expected impact of forthcoming regulations intended to establish limits and tolerance levels for micro toxicants and other essential nutrients in foods and agricultural products.