Comparison of X-Ray Fluorescence, Atomic Absorption, and Gravimetric Methods for the Determination of Lead in Glassware

Methods were developed for determining per cent levels of lead in glassware by atomic absorption and x-ray fluorescence spectroscopy. The procedures were evaluated by comparison with a gravimetric method, using previously analyzed commercial glass samples. For atomic absorption spectrometry, samples are dissolved in a mixture of HF and HNO3. Solutions are nebulized into an acetylene-air flame and absorption is measured at 261.4 nm, a secondary line used in order to avoid large dilutions. For x-ray fluorescence analysis, samples are fused, ground, and then pressed into pellets. The intensity of the Pb Lα line corrected for background is measured. Regression analysis of data obtained with 15 commercial glassware samples shows that there is no significant difference among x-ray fluorescence, atomic absorption, and gravimetric results. Statistical tests performed with data on 4 reference materials indicate satisfactory accuracy for both instrumental methods. The atomic absorption analysis is the fastest and simplest of the 3 methods.