Trace metal contents of acidic, basic and neutral components of a cyclohexanol extract of Kosova Basin lignite

A sample of Kosova Basin lignite was extracted with cyclohexanol. The yield of extract was 19.98 wt%. The extract was fractionated into acidic, basic and neutral components and benzene- and petroleum ether-insoluble fractions. After ashing with HClO 4 and HNO 3 , eleven elements (K, Ca, Mg, Fe, Pb, Zn, Cu, Mn, Cr, Cd and Ni) were analysed by atomic absorption spectroscopy and seven elements (Al, Ba, Sr, Be, B, Ga and V) by inductively coupled plasma optical emission spectroscopy. A majority of the elements (Fe, B, Al, Zn, Pb, Cu, Ca, Mg, Sr, Ga and V) were found concentrated in the acidic and phenol fractions, while K, Ni, Ga and Cu predominated in the amine fraction. The metals thus analysed were associated with heteroatoms.