Electrothermal atomic absorption spectrometric determination of cobalt, copper, lead and nickel traces in aragonite following flotation and extraction separation

A method of determination of Co, Cu, Pb and Ni in nanogram quantities from aragonite is presented. Flotation and extraction of Co, Cu, Pb and Ni is su ggested as methods for elimination matrix interferences of calcium. The met hod of flotation is performed by iron(III) hexamethylenedithiocarbamate, Fe (HMDTC)(3), as a colloid precipitate collector. The liquid-liquid extractio n of Co, Cu, Pb and Ni is carried out by sodium diethyldithiocarbamate, NaD DTC, as complexing reagent into methylisobutyl ketone, MIBK. The electrothe rmal atomic absorption spectrometry (ETAAS) is used For determination of an alytes. The detection limits of ETAAS followed by flotation are: 7.8 ng.g(- 1) for Co, 17.1 ng.g(-1) for Cu, 7.2 ng.g(-1) for Pb and 9.0 mug.g(-1) for Ni. The detection limits of ETAAS followed by extraction are found to be: 1 2.0 ng.g(-1) for Co, 51.0 ng.g(-1) for Cu, 24.0 ng.g(-1) for Pb and 21.0 ng .g(-1) for Ni. (C) 2001 Elsevier Science B.V. All rights reserved.