Fast sequential determination of antimony and lead in pewter alloys using high-resolution continuum source flame atomic absorption spectrometry

Abstract

A simple method has been developed to determine antimony and lead in pewter alloy cups produced in Brazil, using fast sequential determination by high-resolution continuum source flame atomic absorption spectrometry. The samples were dissolved in HCl and H2O2, employing a cold finger system in order to avoid analyte losses. The main resonance line of lead at 217.001 nm and a secondary line of antimony at 212.739 nm were used. The limits of detection for lead and antimony were 0.02 and 5.7 mg L−1, respectively. The trueness of the method was established by recovery tests and comparing the results obtained by the proposed method with those obtained by inductively coupled plasma optical emission spectrometry. The results were compared using a student's t-test and there was no significant difference at a 95% confidence interval. With the developed methods, it was possible to determine accurately antimony and lead in pewter samples. The lead concentration found in the analysed samples was around 1 mg g−1, which means that they are not lead free; however, the content was below the maximum allowed level of 5 mg g−1. The antimony content, which was found to be between 40 and 46 mg g−1, is actually of greater concern, as antimony is known to be potentially toxic already at very low concentrations, although there is no legislation yet for this element.