Screening of foods and related products for toxic elements with a portable X-ray tube analyzer

Capabilities of a portable X-ray tube-based analyzer were evaluated for screening foods, thin films, and ceramic glazes for toxic elements. A beverage spiked with Cr, Cu, and As and cocoa powder spiked with As and Pb could easily be distinguished from unadulterated products when analyzed through their original container walls. With calibration, results for thin films and ceramic glazes yielded accurate Pb results. Limits of detection (LODs) were 0.2-15 and 15 μg cm-2, respectively, for Pb and Cd in thin films and about 2 μg cm-2 for Pb in glazes. With analysis times of 0.5-1 min, sensitivities and LODs were superior to those obtained with radioisotopic X-ray fluorescence analysis. (author)