Giovanni Spini

Determination of inorganic beryllium species in the particulate matter of emissions and working areas

A sequential extraction procedure for separating and determining Be(0), soluble Be(II) inorganic compounds, BeO and beryllium silicates in samples such as particulate matter of emissions and working areas, has been developed. The proposed procedure has been tested on synthetic samples prepared with the inorganic beryllium compounds, in the presence of atmospherical particulate matter sampled in a laboratory of the Department, previously checked for the absence of beryllium. The speciation was then repeated on a sample of fly ash deriving from a solid waste incinerator and on a reference material (Coal Fly ash SRM 1633a, by NIST), followed by an evaluation of matrix spiking and recovery analyses. Performing multiple analyses of the spiked samples assessed the repeatability of the procedure. Quantitative determinations have been made by inductively coupled plasma optical emission spectrometry (ICP-OES) and electrothermal atomic absorption spectrometry (ETAAS). The possible interferences of the most common ions have been investigated. The selective sequential extractions allow one to separate and to determine different inorganic beryllium species, to which a different toxicity and therefore, a different risk are related: it is the case for example of metallic beryllium and beryllium oxide.

Determination of inorganic nickel compounds in the particulate matter of emissions and workplace air by selective sequential dissolutions.

A speciation method of inorganic nickel compounds in airborne particulate, based on selective sequential extractions, is described. It allows the separation and the determination of Ni(0), Ni(II) soluble salts such as sulphate and chloride, Ni insoluble compounds such as nickel oxide and sulphide, to which a different toxicity and therefore a different risk are related. The nickel concentration in each fraction was determined by Flame or Furnace Atomic Absorption Spectroscopy. The proposed procedure has been tested first, on synthetic samples prepared with the different nickel compounds, in the presence of atmospherical particulate matter not containing nickel, in order to take into account the possible matrix influence. The speciation was then repeated on four different samples (fly ash deriving from a solid waste incinerator and three RSMS from NIST: Coal Fly ash SRM 1633b, Urban Particulate 1648, Washington Dust 1649), followed by an evaluation of matrix spiking and recovery analyses. Performing multiple analyses of the spiked samples assessed the repeatability of the procedure.

Sequential extraction procedure for speciation of inorganic selenium in emissions and working areas

A sequential extraction procedure for separating inorganic species of selenium in particulate matter of emissions and working areas, has been developed. The proposed procedure has been tested first on synthetic samples prepared in laboratory with the different selenium salts, then in the presence of atmospherical particulate matter sampled in a laboratory of the department of general chemistry, previously checked for the absence of selenium. Finally the speciation was tested on a reference material (urban particulate matter NIST SRM 1648), certified for the total selenium content. The sample was first treated with the proposed procedure, followed by an evaluation of matrix spiking and recovery analyses. The repeatability of the selenium speciation was assessed by performing multiple analyses of the spiked samples. Quantitative determinations have been made by AAS and voltammetry. The possible interferences of the most common ions have been investigated.

Voltammetric determination of some organic compounds of arsenic reduced at the mercury electrode

Abstract Cyclic voltammetric scans for methylarsonic acid, dimethylarsinic acid and 3-acetamido-4-hydroxyphenylarsonic acid at a mercury electrode in an acidic medium show anodic adsorption waves when the starting potential is sufficiently negative; the related arsines are formed on the electrode. Detection limits are at the micromolar level for the absorption peak found at about −0.1 V vs. SCE for all three compounds. Interferences are discussed.

Spectrophotometric investigation of the reaction of CU(II) and Cu(I) with 1-isonitroso-(1,2,3,4)-tetrahydrophenazine

The reactions of Cu(II) and Cu(I) with 1-isonitroso-(1,2,3,4)-tetrahydrophenazine (HITF) have been studied spectrophotometrically. Both ions form complexes with metal/ligand ratio 1:2. The complex of Cu(I) and ITF can be used for copper determination in the range 2-50 x 10(-6)M, and has been separated as the perchlorate in crystalline form. The spectrophotometric characteristics and the equilibrium constants for the ligand and for the complexes are reported.