Trace metals (Zn, Pb, Cu, Cd) speciation of surface sediments from Makupa creek, coastal Kenya were determined by sequential extraction procedure. The procedure was used to extract the trace metals in sediments geochemical phases (exchangeable, carbonates, Fe-Mn oxides, organic matter/sulphide, and residual). Trace metals analysis was done using ICP/MS. The trace metal speciation results indicated that Pb, Zn, and Cd were mainly associated with the exchangeable, carbonates and Fe-Mn oxides in most of the sampling sites. The highest concentration of the trace metals were associated with Fe-Mn oxides with Zn concentration at 362.5 µg/g, Pb, 31.5 µg/g. Copper was mostly associated with the organic matter/sulphide and carbonate at concentration of 117.5 µg/g and 69.9 µg/g respectively. Generally, trace metals in sediment from Makupa creek were mainly associated with the bioavailable fractions (BAF) and their ranges were: Pb (60%-98%), Zn (90%-99%), Cu (70%-91%). It was found therefore, that there was trace metals enrichment in sediments from Makupa from anthropogenic sources and bioavailable to biota.
Uv-visible and fluorescence spectra of the ligand 1,3-bis(2,2':6',2''-terpyridyl-5-ymethylsulfanyl)propane L and it's iron(II) complex have been investigated for analytical purposes. The two spectra of L and terpy are very similar which confirmed the ability of L to co-ordinate through the six N atoms of L with minimum distortion of the metal ion's octahedral geometry. The ligand-based absorption band of L is shifted to the longer wavelength. It was found that L is able to displace the two terpyridine groups in the complex to give [FeL] 2+ . The high stability of the complex makes it good in spectrophotometry analysis of metals ions in solution. The fluorescence of L was progressively quenched with an increasing concentration of iron(II). This makes L a possible reagent for the quantitative analysis of metal by measuring fluorescence quenching.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.