Speciation of lead alkyl compounds by flame atomic absorption spectrometry with vapour phase sample introduction

Abstract

Flame atomic absorption spectrometry was used to determine tetramethyllead (TML) and tetraethyllead (TEL) using two different reactors. These reactors, which can be employed with conventional instrumentation, were used to volatilise the samples prior to their introduction into the flame. The instrumental and volatilisation parameters were studied in order to obtain the maximum sensitivity and precision. The absolute detection limits obtained were 3.0 ± 0.8 and 3 ± 1 ng for lead as TML and TEL, respectively. Total lead was determined, using a horizontal reactor and when a vertical reactor was used the TML and TEL contents could be determined simultaneously. Synthetic and commercial samples of gasolines were analysed by the proposed method and by a reference method.