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Sequential Extraction Procedure forv Speciation of Inorganic selenium in Emission and Working Areas.
Get PDFA 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
Selective sequential dissolution for the determination of inorganic indium compounds in the particulate matter of emissions and workplace air
No full textA speciation method was developed for the determination of inorganic indium compounds in the particulate matter of emissions and workplace, based on selective sequential extractions. In(III) soluble salts such as sulphate and chloride, In and In(III) insoluble compounds such as oxide, sulphide and indium arsenide were separated and determined. These are the main inorganic indium compounds that are expected to be present in the atmospheric particulate of the industrial production of indium and in the manufacture of indium compounds. The procedure has been tested on spiked Coal Fly ash SRM 1633a and Urban Particulate NIST SRM 1648, whose consensus value for the total indium content were reported. The indium recovery was in the range 93 % - 105%. Indium was determined by Optical and Mass Spectrometry Inductively Coupled Plasma, depending on its concentration in the samples
Determination of Inorganic Thallium Compounds in the Particulate Matter of Emissions and Workplace Air by Sequential Dissolution
No full textInorganic thallium compounds in the atmospheric particulate matter of emissions and in the workplace air of specific industrial production can be determined through selective sequential extractions: Tl(I) is separated from Tl(0) and Tl(III) in the first step, Tl(0) in the second one while in the final extraction both Tl(III) soluble and insoluble compounds are determined. The procedure has been tested on 1633a Coal Fly Ash standard reference material. The thallium recovery was in the range 91 – 98%
Studio delle concentrazioni degli elementi in tracce e della loro distribuzione granulometrica nel particolato atmosferico di zone urbane e industrializzate mediante analisi per attivazione neutronica.
No full textSequential Extraction Procedure for Speciation of Inorganic Cadmium in Emissions and Working Areas
No full textA sequential extraction procedure for separating and concentrating soluble Cd(II) salts, CdO, Cd(0), CdS, CdSe
and cadmium-aluminosilicates, has been developed for the cadmium speciation in samples such as particulate matter
in emissions and working areas. The proposed procedure has been tested first on synthetic samples prepared in a
laboratory with the different cadmium salts, then also in the presence of atmospherical particulate matter sampled in
a laboratory of the Department of Analytical Chemistry, previously checked for the absence of cadmium. Finally the
speciation was tested on particulate matter collected near the emission of a power plant fed by coal, after emission’s
treatment by electrostatic precipitator: matrix spiking and recovery analyses have been evaluated and the repeatability
of the cadmium speciation was assessed by performing multiple analyses of the spiked samples. Quantitative
determinations have been made by FAAS and GFAAS through the standard additions method
Characterization of an Enzyme linked Immunosorbent Assay for Aflatoxin B1 based on commercial reagents
No full textDetermination of Metallic Cobalt in the Atmosphere
No full textA method based on sequential and selective dissolution to separate metallic cobalt, characterized by the hifhest toxicity, from the other different chemical species present in the air particulate matter, is described. Possible interferences are discussed. The procedure allows to determine separately the sum of the insoluble and water soluble cobalt compounds
Determination of Inorganic Nickel Compounds in the Particulate matter of Emissions and Workplace Air by Selective Sequential Dissolutions
No full textA 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 sulfide, 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
Solid-phase extraction of PFOA and PFOS from surface waters on functionalized multi-walled carbon nanotubes followed by UPLC-ESI-MS
Get PDFThis is the first report on the analytical application
of multiwalled carbon nanotubes (MWCNTs) as solid-phase
extraction (SPE) sorbents for determination in surface waters,
at the nanograms per litre level, of perfluorooctanoic acid
(PFOA) and perfluorooctane sulfonate (PFOS), the two predominant
contaminants among the perfluorinated compounds
detected. After the preconcentration step, the quantification
was achieved by ultraperformance liquid chromatography–
electrospray ionization mass spectrometry. To increase the
extraction efficiency towards these amphiphilic compounds,
MWCNTs were derivatized with amino-terminated alkyl
chains, thus producing a mixed-mode material (MWCNT-RNH2)
combining hydrophobic affinity and anion-exchange
properties. Experiments with distilled, tap and river water
(pH 3) spiked at different concentrations (10, 15, 30, 100,
200 and 500 ng L-1) provided absolute recoveries in the range
71–102 % (n=3, relative standard deviations less than 10 %).
Analytes were eluted in a single fraction with 6 mL methanol
(3×10-4 M NaOH). The within-laboratory reproducibility of
the MWCNT-R-NH2 SPE sorbent was evaluated with raw
river water, and relative standard deviations less than 15 %
were obtained (n=4). Preconcentration factors up to 125
(500-mL sample) made it possible to quantify PFOA and
PFOS at low nanograms per litre levels in naturally contaminated
river water. The method quantification limits of
10 ng L-1 for PFOA and 15 ng L-1 for PFOS were well below
the advisory levels for drinking and surface waters. Comparison with non-derivatized MWCNTs highlighted the
role of functionalization in improving the adsorption affinity
towards these contaminants. MWCNT-R-NH2 maintained
their extraction capability for at least eight repeated
adsorption/desorption cycles
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