[GFAAS determination of trace lead in toothpaste using L'vov platform].

Sensitivity in determining low melting point metals is highly improved by means of platform technique in graphite furnace AAS. In this paper we describe a method of determining trace lead in toothpaste by this technique. The method of making the platform and the selection of the platform coating were discussed and the results with and without the platform were compared. The optimum ashing temperature, atomization temperature and experimental conditions were investigated. The interference of large amount Al and Ca in the matrix on determination of trace lead can be minimized by using platform technique. The precision of about 0.9% and detection limit of about 15 ng obtained by this improved method are much better than those by methods without platform.