Proposal for a metal speciation study in sediments

A new five-step extraction procedure for metal speciation has been applied to two sediments, one marine and the other lakustrine. This procedure has been developed to distinguish the metal fraction bound to the organic matter from that bound in the sulphide form. The extradant solutions were: 1 mol 1−1 ammonium acetate; 1 mol 1−1 hydroxylammonium chloride (1:1 in 25% (v/v) acetic acid); 0.1 mol 1−1 hydrochloric acid; 0.5 mol 1−1 sodium hydroxide; and 8 mol 1−1 nitric acid. The metal concentration (copper, manganese, nickel, lead and zinc) in the extracts was determined by flame atomic absorption spectrometry.