DETERMINATION OF LEAD AND COPPER IN KEROSENE BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY - STABILIZATION OF METALS IN ORGANIC MEDIA BY A 3-COMPONENT SOLUTION

The instability of copper and lead in kerosene and in analytical organic solutions is the main problem with their direct determination. When propan-1-ol is added to a mixture of kerosene and water a homogenous three-component solution is obtained. It was verified that the metals in this solution placed in an autosampler cup are stable for at least 3 h in a closed calibrated flask and remain stable for at least 24 h. The three-component solutions containing purified kerosene and enriched with metallic ions in aqueous solution or with copper or lead cyclohexanebutyrate or tetraethyllead are also stable. In spite of some differences in the absorption pulses, the maximum pyrolysis temperatures, characteristic masses and precision are similar for the three-component solutions in comparison to aqueous solutions.