Search results for "Aqua regia"
showing 6 items of 16 documents
Cold vapour atomic fluorescence determination of mercury in milk by slurry sampling using multicommutation
2004
Abstract A highly sensitive mechanized method has been developed for the determination of mercury in milk by atomic fluorescence spectrometry (AFS). Samples were sonicated for 10 min in an ultrasound water bath in the presence of 8% (v/v) aqua regia, 2% (v/v) antifoam A and 1% (m/v) hydroxilamine hydrochloride, and after that, they were treated with 8 mmol l −1 KBr and 1.6 mmol l −1 KBrO 3 in an hydrochloric medium. Atomic fluorescence measurements were made by multicommutation, which provides a fast alternative in quality control analysis, due to the easy treatment of a large number of samples (approximately 70 h −1 ), and is an environmentally friendly procedure, which involves a waste ge…
A multicommutated flow system for determination of bismuth in milk shakes by hydride generation atomic fluorescence spectrometry incorporating on-lin…
2004
Abstract A highly sensitive method was developed for determination of bismuth in milk shakes by multicommutation hydride generation atomic fluorescence spectrometry (HG-AFS) based on off-line sonication for 10 min with aqua regia 8% (v/v) and on-line waste treatment. The instrumentation and chemistry variables were studied in order to provide the best performance. The limit of detection in the original samples, established for a probability level of 99.6% (k = 3), was 1.67 ng/g Bi. The method provides a fast alternative in control analysis with a sampling throughput of 72 h as compared with 31 h obtained by the classical continuous measurement. Additionally, multicommutation reduces waste g…
The contamination legacy of a decommissioned iron smelter in the Italian Alps
2018
The economically important activity of metal processing can tend to contribute to the degradation of the environment. Smelting is an important source of contaminants, dispersing large quantities of potentially toxic elements (PTE) and coproducts into the environment. Soils in the vicinity of smelters frequently contain high concentrations of PTE. In terms of the quantities processed, the major PTE are iron (Fe), aluminium (Al), copper (Cu), lead (Pb), manganese (Mn), and zinc (Zn); of these Cu, Pb and Zn are, potentially, highly hazardous elements. The general problem addressed by this study is to determine if the PTE concentration in the soils of an area downwind from a decommissioned iron…
Background element content in the lichen Pseudevernia furfuracea: a comparative analysis of digestion methods
2019
In bioaccumulation studies, the interpretation of pollutant contents in the target biomonitor has to be performed by assessing a deviation from an unaltered reference condition. A common strategy consists in the comparison with background element content (BEC) values, often built up by uncritically merging methodologically heterogeneous data. In this respect, the acid digestion of samples was identified as a major step affecting BEC data. Here, the analytical outcomes of two acid mixtures were compared on a set of matched paired samples of the lichen Pseudevernia furfuracea, a widely used biomonitor for which BEC values based on partial digestion were previously provided. The standard refer…
Isotope dilution inductively coupled plasma quadrupole mass spectrometry in connection with a chromatographic separation for ultra trace determinatio…
2000
An isotope dilution inductively coupled plasma quadrupole mass spectrometric (ID-ICP-QMS) method was developed for the simultaneous determination of the platinum group elements Pt, Pd, Ru, and Ir in environmental samples. Spike solutions, enriched with the isotopes 194Pt, 108Pd, 99Ru, and 191Ir, were used for the isotope dilution step. Interfering elements were eliminated by chromatographic separation using an anion-exchange resin. Samples were dissolved with aqua regia in a high pressure asher. Additional dissolution of possible silicate portions by hydrofluoric acid was usually not necessary. Detection limits of 0.15 ng x g(-1), 0.075 ng x g(-1), and 0.015 ng x g(-1) were achieved for Pt,…
Comparison of ultrasound-assisted extraction, microwave-assisted acid leaching and reflux for the determination of arsenic, cadmium and copper in con…
2002
Extraction methods for the determination of arsenic, cadmium, and copper in contaminated soil samples by Zeeman effect electrothermal atomic absorption spectrometry have been compared. The determination of cadmium and copper in ultrasound-assisted aqua regia extracts of contaminated soil SRMs by ETAAS, using a mixture of NH4H2PO4 and Mg(NO3)2, for cadmium, and a mixture of Pd and Mg(NO3)2, for copper, as a matrix modifier, was carried out with high accuracy and precision (RSD < 5.1%). The analysis of SRM 2711 failed to obtain the certified concentrations of Cd and Cu by microwave and reflux methods, respectively. The determination of arsenic was performed successfully in low chloride concen…