A. Traini

Chemical characterisation of ancient pottery from south of Italy by inductively coupled plasma atomic emission spectroscopy (ICP-AES) statistical multivariate analysis of data

Chemical characterisation has been carried out on 58 fragments of archaeological pottery from pre-classical sites in Apulia and Lucania, regions in southern Italy. Fourteen elements were determined by atomic emission spectroscopy by using inductively coupled plasma source. Statistical techniques, such as principal component analysis and clustering analysis, have been utilised to define grouping of different pottery items. Tests performed showed that the analysed shards were differentiable mainly by age and provenance.

XPS, ICP and DPASV analysis of medieval pottery — Statistical multivariate treatment of data

Medieval ceramic sherds have been studied by inductively coupled plasma (ICP) emission spectroscopy and X-ray photoelectron spectroscopy (XPS) in order to acquire knowledge about technological achievements in pottery production in Apulia during the Middle Ages. The XPS results allow to characterize the surface glazes, which are transparent owing to the presence of PbO or opaque-white in case of Sn addition. The study of coloured glossy surfaces, after an optimized chemical etching, has also shed light on the pigment nature of the painted decorations, whose red colour is to be attributed to the presence of Pb3O4 and not of Fe oxides. Quantitative determinations were performed by ICP measurements on samples of differently coloured glazes, clayey slips and ceramic bulks. Pb and Cu, present in one green glaze, were also determined by differential pulsed anodic stripping voltammetry (DPASV). The analytical results were treated by different statistical techniques of multivariate analysis.

A multianalytical study of archaeological faience from the Vesuvian area as a valid tool to investigate provenance and technological features

The investigation was aimed at defining the compositional and structural characteristics of a group of monochrome blue faiences recovered in Pompeii to assess provenance on the basis of their technological features. Different complementary analytical techniques were used: Scanning Electron Microscopy (SEM) to investigate the morphological aspects of the samples and in particular of the interfaces, micro-Raman Spectroscopy and XRPD to identify crystalline phases and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) to assess the elemental composition due to its sensitivity to a wide range of elements and the adequate lateral resolution. Statistical data treatment of the elemental concentrations of both the ceramic bodies and the glazes allowed us to classify the objects into compositional groups and to verify the previously established archaeological hypothesis suggesting an Egyptian provenance for faience of Pompeii.

FLY ASH REACTIVITY Formation of hydrate phases

In this study the process of hydration of fly ash, produced by a municipal solid waste (MSW) incinerator, is examined in water and in a solution enriched with Ca(OH)2. The examined fly ash samples are characterized by a high content of alkaline chlorides and anhydrite and by remarkable amounts of heavy metals. Investigations using differential thermal analysis/thermogravimetry (DTA/TG) and X-ray diffractometry (XRD)show particular kinetics of the formation of the ettringite phase. The development of such a hydrated phase is much more intense in the presence of an excess of Ca(OH)2so as to consume the ‘free’ sulphate in the case of the more reactive fly ash. Experimental results from thermal analysis and X-ray diffractometry show the presence of different hydrated phases during the interaction between fly ash and aqueous solution. The analytical determinations, related to the aqueous solution, point out an interesting decrease in concentration of metals Pb, Zn and Cr(VI), relating to the middle period of the interaction.

Analysis of heavy metals in atmospheric particulate by ion chromatography

Cu, Ni, Zn, Co, Fe+2, Mn, Cd, Fe+3 and Pb are easily separated and detected in isocratic mode by ion chromatography with post-column derivatization using a bifunctional ion-exchange column and an eluent formed by oxalic acid (28 mM) and sodium nitrate (250 mM). The separation is optimised by using a suggested sample solution containing a given concentration of chloride. Detection limits were 10-15 ppb for all the metals except for cadmium and lead, for which detection limits of 30 and 60 ppb were found, respectively. The method was tested on an atmospheric particulate certified sample. The measured values were in good agreement with certified values. Real samples of atmospheric particulate from industrial and urban sites were analysed and the results are discussed.

Characterisation of mineral waters by pattern recognition methods

Eighty-three samples of mineral water from four different wells in the same district were analysed for 23 parameters. Nineteen parameters were chosen for multivariate analysis. Principal components analysis provided a feature reduction to two or three dimensions without substantial loss of information. The data set is well separated into four clusters using hierarchical and non-hierarchical methods; samples from different wells are generally assigned to different clusters.

HPTLC separation and densitometric determination of some metallic dithizonates at subnanogram level: applications to real samples

Abstract Some metallic ions have been separated as dithizonates and determined in situ by densitometric automatic scanning of the plate in quantities down to 0.5 ng. High efficiency plates have been employed whose theoretical plate height relative to the chosen conditions was found to be about 20 μ. Rf values of Co, Pb, Cu, Ni, Zn, Hg are 0.23, 0.38, 0.40, 0.46, 0.53, 0.65 respectively. Conditioning by H2SO4 leads to improvement in the separation and conditioning by NH3 separates Hg from all other dithizonates. Some examples of real sample analysis (Zn, Co, Ni in soaps, Vitamin B12, Hg in human urine) are reported.

Analysis of polycyclic aromatic hydrocarbons in the atmospheric particulate: focused microwaves for a faster extraction method

In this paper, improvements obtained by using focused microwaves for extraction, in the analysis of polycyclic aromatic hydrocarbons (PAHs) adsorbed on particulate matter, are discussed. The method was tested on the following PAHs, which are considered to be among the most harmful with regard to carcinogenicity: benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene. The extraction of PAHs and concentration of the sample can be performed in 3 h with a recovery of at least 70% and a maximum standard deviation of 4%. These steps are followed by clean-up on a SPE (solid-phase extraction) cartridge and analysis by GC-MS. Real samples collected in the urban area of Bari were analysed according to the proposed procedure.

Automatic determination of calcium and magnesium in water

Magnesium and calcium may each be determined in water by an automatic spectrophotometric method. At 571 nm with an excess of Eriochrome Black T as metallochromic agent, the variation m absorbance is proportional to the magnesium concentration regardless of the calcium concentration. By addition of MgEDTA to displace the calcium from its CaEBT complex, this element may be determined at the same wavelength. For 3-25 ppm of magnesium and 5-40 ppm calcium, the standard deviation was about 4%. The apparatus is described.

Hexamethylphosphoramide as Analytical Reagent: Simultaneous Determination of Cobalt, Iron and Nickel

Abstract Hexamethylphosphoramide (HMPA) gives, in aqueous solutions in the presence of SCN− ions, complexes with many metal ions, which absorb in the visible region of spectrum. The spectra have been studied in function of ligand concentration and pH for Co, Ni and Fe complexes. For the Co complex an equation was found that describes the behaviour of the absorption vs. SCN− and HMPA concentration. Absorption follows Lambert-Beer law and can be used for analytical determinations. Analysis of solutions containing Ni and Co in various ratios of concentration has been performed and results are discussed. Co, Ni and Fe content of an alloy has been measured by this way.