F. Baffi

Trace metals in sediments from the Ligurian Coast, Italy☆

Abstract The content of trace metals (Fe, Cd, Cu, Ni, Pb and Cr) in the Ligurian Coastal Area were acid leached and analysed by the atomic absorption method. In the stations in front of Genoa, with the maximum organic carbon content, Cr, Cu and Pb show a significant correlation between the leachable fraction with cold reagents and the organic carbon content of the sediment. Significant linear correlations of metals to total Fe were obtained for unpolluted sediments.

Ion-exchange separation and atomic-absorption determination of fifteen major, minor and trace elements in silicates.

A scheme of ion-exchange separation of fifteen elements (major, minor and trace) determined mainly by atomic-absorption spectrophotometry (Ti by colorimetry) is applied to rock, mineral and ceramic analysis. Mn, Cu, Co, Fe and Zn are separated on an anion-exchanger and Li, Na, K, Mg, Ca, Sr, Ti, Al, Ni and Ba on a cation-exchanger. The method has been tested by analysis of a synthetic mixture of the fifteen ions in the ratios in common rock samples, and of various international standards (100-mg samples).

The determination of heavy metals in the ligurian sea. I, the distribution of Cu, Co, Ni and Cd in surface waters

Abstract Determinations of Cu, Co, Ni and Cd were carried out on 39 samples of surface seawaters from the Ligurian Sea, nearshore and offshore, between the Isola Capraia and Imperia. The concentrations of trace elements have been established employing the analytical method suggested by Le Meur and Courtot-Coupez (1973), by means of concentration of the sample by chelating resin, solvent extraction of the eluate and then by quantitative determination by AAS. The results obtained with this technique probably refer to ionic forms of the elements only. The Co concentration was lower than 0.15 μg 1 −1 in 32 samples, with an average of 0.49 μg 1 −1 for the others. For Cd, the greater number of samples had a content lower than 0.05 μg 1 −1 . For the others the mean concentration was 0.13 μg 1 −1 . The Ni had a mean concentration of 0.93 μg 1 −1 and the average Cu content was 1.43 μg 1 −1 . Our data are in agreement with the values published by authors who have employed the same analytical technique. We observed that the offshore samples present a concentration lower than that in the nearshore samples.

Organic acid solutions in the chromatography of inorganic ions-IV: cation-exchange of Mn(II), Cd(II), Co(II), Ni(II), Cu(II), Al(III) and Fe(III) in tartrate media.

The cation-exchange behaviour of Mn(II), Cd(II), Co(II), Ni(II), Cu(II), Al(III) and Fe(III), in tartaric acid media was studied. Separations of Fe(III), Cu(II), Ni(II), Co(II), Cd(II) and Mn(II) on Dowex 50W X8 have been achieved.

Determination of trace amounts of zirconium in silicates by cation-exchange chromatography and spectrophotometry with xylenol orange.

An ion-exchange scheme and colorimetric determination with Xylenol Orange are used for estimating traces of zirconium in silicate rocks.

The determination of heavy metals in the Ligurian Sea. II. The geographical and vertical distribution of Cd, Cu, and Ni☆

Abstract Cd, Cu, and Ni were determined in surface and deep-water samples from 15 stations in the Ligurian Sea. The samples were preconcentrated in chelating resins and quantitatively determined by atomic absorption spectrophotometry. The variability of the concentrations with depth was in general not significant compared with the variability of the analytical method, except at the station nearest the shore. Statistical analyses of the mean concentrations show also no significant regional variations in Cu, Ni, and Cd.

Correspondences between hydrology and particulate metal concentrations along mediterranean vertical profiles

Abstract Results concerning the vertical profiles of some heavy metal concentrations in Mediterranean suspended particulate matter, collected during an oceanographic cruise (May–June 1991), are discussed. The chemical analyses were carried out according to plasma atomic emission spectroscopy. The research was completed with hydrological data, which indicate Levantine Intermediate Water to be present. Correspondences between temperature and salinity profiles and chemical results pointed out that, in some cases, the heavy metals concentration in the particulate matter (μg g−1 of particulate, dry weight) could be a tracer, together with hydrological parameters, when studying the displacement of seawater masses. In fact, in correspondence with the Levantine layer, in two stations the heavy metal concentration average values are greater than the average values relative to surface and deep layers, and in three stations, ‘unusual’ correlations between some metals in the intermediate layer confirm the presence of a different kind of particulate matter.

The Determination of Heavy Metals in the Ligurian Sea. III. Distribution of Copper, Iron, and Nickel in the 0–200 Metre Layer in Open Sea

Abstract Dissolved Cu, Fe and Ni were determined in sea water samples from 9 stations in the Ligurian Sea located along the two traverses Imperia-Capo Corso and Nice-Calvi and at depths between 0 and 200 m. The samples were preconcentrated from small volumes of sea water by complexation with ammonium pyrrolidine-dithiocarbammate (APDC), extraction with CCl4 and determination by AAS with electrothermal atomisation. The geographical distribution shows that in the central part of the inner traverse there is a maximum of Cu and Fe concentration; the vertical distribution shows no significant depletion of the dissolved elements in the epithalassa. The results allow for a first approach to the more general problem of the distribution of the trace elements in the Ligurian Sea.

High-pressure liquid chromatography of trace elements: Determination of terbium in terbium doped gadolinium oxide sulphide phosphors

SummaryA detailed study of isocratic and gradient elution separations of lanthanides has been carried out. Analyses of industrially and scientifically interesting products such as luminescent phosphors have been carried out by gradient elution with DL-2-hydroxyisobutyric acid. The determination of small amounts of terbium in gadolinium oxide sulphide phosphors is described in which an HCl solution was eluted through a stainless steel column packed with microparticulate silica, with bonded cation-exchange groups. Complete separation of gadolinium and terbium is achieved. Detection is with a variable wavelength detector following post-column complex formation with 4-(2-pyridylazo)-resorcinol monosodium salt. Results obtained on test solutions show good reproducibility and sensitivity and the method may be considered sufficiently reliable to be used in routine quality control procedures.

Seasonal and depth variations of copper, iron and nickel in ligurian coastal waters

Abstract The aim of this work is to study the seasonal variation of iron, copper and nickel in connection with those of other environmental parameters which characterize the coastal system studied; in particular, the phytoplankton biomass. Sampling was carried out from January to October with monthly periodicity, at a station 2 miles offshore of Portofino, Italy, to depths of 200 m. The results indicate that the concentrations of copper, iron and nickel in particulate matter show a marked increase compared to values reported in the literature for the open seawater of the Mediterranean. It is also possible to determine a relationship between the three metals and the seasonal and depth variations. In the particulate matter, there is a direct relationship between the phytoplankton biomass and the heavy metals in the photic layer.