Determination of Lead in Beer Using Zeeman Background-Corrected Graphite Furnace Atomic Absorption Spectrometry

Abstract

Because of its toxicity and the potential for adverse health effects, lead has attracted widespread interest in its occurrence in the environment, drinking water, and many comestibles, including alcoholic beverages. Its accurate analysis at very low levels in complex matrices such as beer is subject to many difficulties from interferences and demands specialized equipment and techniques. Graphite furnace atomic absorption spectrometry has been successfully used for the analysis of lead in biological samples and has previously been applied to beer. In recent times, the reassessment of lead's human health implications has prompted North American regulatory agencies to lower the acceptable levels of lead contamination in the environment and, particularly, in drinking water. Consequently, this has renewed the requirements for lower detection limits and improved accuracy in analyses. Earlier studies have shown that with modern-day standards for equipment and materials used in beer production and packaging, beers contain only trace levels of lead and generally were below the newly established guidelines for drinking water. There is need, however, for improved accuracy in lead determinations. This method achieves that by combining an appropriate matrix modifier, platform atomization, peak area integration, Zeeman background correction, insertion of a cool-down step before atomization, and the use of the alternate wavelength (283.3 nm) for lead. The method has a limit of detection of 0.87 μg/L and a limit of determination of 2.1 μg/ L.