Identification of Lead and Other Elements in Ceramic Glazes and Housewares by 109Cd-Induced X-Ray Fluorescence Emission Spectrometry

Abstract

Radioisotope x-ray fluorescence spectrometry was investigated as a potential screening method for Pb and other elements in housewares. Thirty-six commercial houseware items and 87 ceramic test tiles (85 fired with hobby glazes and 2 blank bisques) were examined qualitatively for the presence of Pb by using 109Cd-induced L x-ray fluorescence emission spectrometry. For the housewares, the technique provided fast, nondestructive analysis of areas with about 10 cm diameters (general regions) to about 4 mm diameters (isolated design regions). Pb was found in 25 of 28 ceramicware items, in all 8 other housewares, and in all the test-tile glazes above the limit of detection of 1 count per second (cps) for Pb L beta x-rays. For housewares, Pb identification did not always correspond to Pb leachability. For 68 test-tile glazes labeled as containing Pb (39 of which were also labeled 'dinnerware safe' or 'safe for food containers'), count rates ranged from 290 to 730 cps, whereas for the other 17 glazes labeled (with one exception) 'non-toxic,' much lower count rates (5-61 cps) were obtained. Other elements found in the housewares or test glazes were As, Au, Ca, Co, Cr, Cu, Fe, Mn, Nb, Ni, Rb, Sr, Y, Zn, and Zr.