Search results for "Coupled"

Procedures of Separation and Pre‐concentration for Molybdenum Determination Using Atomic Spectrometry—a Review

2004

Abstract The literature concerning the improvement of atomic and ionic procedures for molybdenum determination through separation and pre‐concentration were updated. Analytical procedures based on flame atomic absorption spectrometry (AAAS), electrothermal or graphite furnace atomic absorption spectrometry (GFAAS), inductively coupled plasma optical emission spectrometry (ICP‐OES), and inductively coupled plasma mass spectrometry were reviewed taking into consideration the preliminary steps, which can enhance the selectivity and sensitivity based on co‐precipitation, solvent extraction, and solid‐phase extraction. Both in‐batch and on‐line procedures were considered.

Isovaleraldehyde degradation using UV photocatalytic and dielectric barrier discharge reactors, and their combinations

2015

International audience; The abatement of isovaleraldehyde present in air was carried out in UV photocatalytic and dielectric barrier discharge reactors (and their combinations) for concentrations up to 150 mg C m−3 and air flow rates ranging from 4 to 10 m3 h−1. A kinetic study was performed following a Langmuir–Hinshelwood model. Photocatalytic treatment of an isovaleraldehyde and isovaleric acid mixture showed a clear inhibition of isovaleric acid abatement in presence of isovaleraldehyde. Dielectric barrier discharge treatment of isovaleraldehyde showed an increase of removal efficiency with applied voltage and a decrease with air flow rate and inlet concentration. Moreover, introduction…

Accurate determination of element species by on-line coupling of chromatographic systems with ICP-MS using isotope dilution technique

1998

Abstract The instrumental design for coupling different liquid chromatographic systems such as ion, reversed phase, and size exclusion chromatography as well as capillary gas chromatography, with ICP-MS for the determination of element species is described. For accurate analyses obtaining ‘real time’ concentrations of chromatographic peaks, the isotope dilution mass spectrometric (IDMS) technique is applied. Two different spiking modes are possible, one using species-specific and another one using species-unspecific spike solutions of isotope-enriched labelled compounds. The species-specific mode is only possible for element species well defined in their structure and composition, for examp…

Isotope-dilution ICP-MS for trace element determination and speciation: from a reference method to a routine method?

2003

This critical review discusses the conditions under which inductively coupled plasma-isotope dilution mass spectrometry (ICP-IDMS) is suitable as a routine method for trace element and element-speciation analysis. It can, in general, be concluded that ICP-IDMS has high potential for routine analysis of trace elements if the accuracy of results is of predominant analytical importance. Hyphenated techniques with ICP-IDMS suffer both from lack of commercially available isotope-labeled spike compounds for species-specific isotope dilution and from the more complicated system set-up required for species-unspecific ICP-IDMS analysis. Coupling of gas or liquid chromatography with species-specific …

ICP-MS multielement determination in fly ash after microwave-assisted digestion of samples.

2001

A microwave assisted digestion procedure has been developed for dissolution of fly ash samples prior to the inductively coupled plasma-mass spectrometric determination of their elemental composition. The developed methodology was validated by carrying out the analysis of two high-silicate containing reference materials (CRM 134R sewage amended soil and NIES JR 1 rock) and by means of the comparison between results found by microwave-assisted digestion and ICP-MS of fly ash samples with those found by neutron activation analysis (NAA) for Sb, Cs, Cr, Co, Fe, U and Zn determination. The method developed can be recommended for routine multielement analysis of fly ash.

An ultrasound-assisted digestion method for the determination of toxic element concentrations in ash samples by inductively coupled plasma optical em…

2007

Abstract A method of ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) used for the determination of toxic element concentrations (arsenic, barium, cobalt, copper, lead, nickel, strontium, vanadium and zinc) in ash samples was developed. All the measurements were performed in robust plasma conditions which were tested by measuring the Mg(II) 280.270 nm/Mg(I) 285.213 nm line intensity ratios. The highest line intensity ratios were observed when a nebulizer gas flow of 0.6 L min−1, auxiliary gas flow of 0.2 L min−1 and plasma power of 1400 W were used for radially viewed plasma. The analysis of SRM 1633b showed that the ultrasound-ass…

Development of a species-unspecific isotope dilution GC-ICPMS method for possible routine quantification of sulfur species in petroleum products.

2008

Inductively coupled plasma mass spectrometry (ICPMS) hyphenated with capillary gas chromatography was applied for sulfur multispecies determination in petroleum products by species-unspecific isotope dilution mass spectrometry (IDMS). To guarantee a stable and continuous addition of the spike into the GC-ICPMS system, a special dosing unit was designed and synthesis of a (34)S-labeled dimethyldisulfide spike from (34)S-enriched elemental sulfur in the milligram range was developed. The sample was mixed with an internal standard for spike mass flow calibration. From the mass flow chromatogram obtained by species-unspecific GC-ICP-IDMS, determination of all separated sulfur species and of the…

Determination of chromium in foods by flame atomic absorption and inductively coupled plasma spectrometry

1989

Statistical characterisation of heavy metal contents inParacentrotus lividusfrom Mediterranean Sea

2014

This work focuses on the estimation of Hg, As, Cr, Ni, Cu, V, Cd and Pb by inductively coupled plasma mass spectrometry in 135 adult specimens of Paracentrotus lividus collected in different coastal areas of Sicily (Gela, Punta Secca, Ragusa (RG), Siracusa, Priolo, Catania, Messina, Milazzo, Brolo and Filicudi), in order to monitor the Mediterranean marine ecosystem by use of sea urchin as bioindicator. Moreover, the paper deals with the statistical classification of the tested samples according to the sampling area based on metal concentrations. The descriptive statistics findings were obtained and, a starting multivariate matrix was built. Data-sets were subjected to Kruskal-Wallis test t…

Probes for studying cholesterol binding and cell biology.

2011

Cholesterol is a multifunctional lipid in eukaryotic cells. It regulates the physical state of the phospholipid bilayer, is crucially involved in the formation of membrane microdomains, affects the activity of many membrane proteins, and is the precursor for steroid hormones and bile acids. Thus, cholesterol plays a profound role in the physiology and pathophysiology of eukaryotic cells. The cholesterol molecule has achieved evolutionary perfection to fulfill its different functions in membrane organization. Here, we review basic approaches to explore the interaction of cholesterol with proteins, with a particular focus on the high diversity of fluorescent and photoreactive cholesterol prob…