ICP-OES) And Mass Spectrometry Research Articles

Association of Metallic and Nonmetallic Elements with Fibrin Clot Properties and Ischemic Stroke.

Objectives-Metallic elements and fibrin clot properties have been linked to stroke. We examined metallic and nonmetallic elements, fibrin clot lysis time (CLT), and maximum absorbance (Absmax) in relation to ischemic stroke. Design-A case-control study of ischemic stroke patients vs. healthy individuals. Subjects and Methods-Plasma and serum were collected from 260 ischemic stroke patients (45.0% women; age, 68 ± 12 years) and 291 healthy controls (59.7% women; age, 50 ± 17 years). Fibrin CLT and Absmax were measured using a validated turbidimetric assay. Serum elements were quantified by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). Data were analyzed by bivariate correlations and multiple or logistic regression. Results-In female stroke patients, copper, lithium, and aluminum were significantly lower compared with controls; in male stroke patients, potassium was lower, and beryllium was elevated. In female and male stroke patients, iron, zinc, nickel, calcium, magnesium, sodium, and silicon were significantly lower, while strontium was elevated. Positive correlations between fibrin clot properties and metals, observed in healthy controls, were lost in ischemic stroke patients. In multivariate regression analysis, fibrin CLT and/or Absmax was associated with zinc, calcium, potassium, beryllium, and silicon in stroke patients and with sodium, potassium, beryllium, and aluminum in controls. In logistic regression analysis, stroke was independently associated with lithium, nickel, beryllium, strontium, boron, and silicon and with sodium, potassium, calcium, and aluminum but not with fibrin CLT/Absmax. Conclusions-Various elements were associated with fibrin clot properties and the risk of ischemic stroke. Lithium, sodium, calcium, and aluminum abrogated the association of fibrin clot properties with ischemic stroke.

The use of nitrous oxide whippets as a recreational drug: Hidden health risks.

Whipped cream canisters, also known as nitrous oxide whippets, are traditionally used in the culinary arts to prepare food foams. In recent years, however, these gas canisters have been cracked open and inhaled to produce a "legal" high. Users of these whippets have reported the presence of an oily residue containing metallic particles. This contamination was investigated using liquid chromatography-, gas chromatography- and inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). The particulate matter was also analyzed by scanning transmission electron microscopy (STEM) combined with energy-dispersive X-ray spectroscopy (EDX). The presence of cyclohexyl isothiocyanate was confirmed at a maximum concentration of 67 μg per whippet. ICP-MS and ICP-OES analysis revealed the presence of mainly iron and zinc, but also, traces of aluminum, chromium, cobalt, nickel, and lead were found. STEM-EDX analysis confirmed the presence of nano-sized particles containing iron and zinc. When simulating inhalation, using the multiple path particle dosimetry model, it was confirmed that these nano-sized particles can reach the deeper parts of the lungs. Most users assume that inhaling a food-grade nitrous oxide whippet for a "legal" high poses no risks. However, this research shows that users are exposed to cyclohexyl isothiocyanate, a substance classified as a respiratory sensitizer. The presence of zinc in the particulate matter could potentially be linked to lung lesions.

Impurities in commercial titanium dental implants – A mass and optical emission spectrometry elemental analysis

ObjectiveTitanium (Ti) is considered bioinert and is still regarded as the “gold standard” material for dental implants. However, even ‘commercial pure’ Ti will contain minor fractions of elemental impurities. Evidence demonstrating the release of Ti ions and particles from ‘passive’ implant surfaces is increasing and has been attributed to biocorrosion processes which may provoke immunological reactions. However, Ti observed in peri-implant tissues has been shown to be co-located with elements considered impurities in biomedical alloys. Accordingly, this study aimed to quantify the composition of impurities in commercial Ti dental implants. MethodsFifteen commercial titanium dental implant systems were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). ResultsThe elemental composition of implants manufactured from commercially pure grades of Ti, Ti-6Al-4V, and the TiZr alloy (Roxolid) conformed to the respective ISO/ASTM standards or manufacturers´ data (TiZr/Roxolid). However, all implants investigated included exogenous metal contaminants including Ni, Cr, Sb, and Nb to a variable extent. Other contaminants detected in a fraction of implants included As and the radionuclides U-238 and Th-232. SignificanceAlthough all Ti implant studies conformed with their standard compositions, potentially allergenic, noxious metals and even radionuclides were detected. Since there are differences in the degree of contamination between the implant systems, a certain impurity fraction seems technically avoidable. The clinical relevance of these findings must be further investigated, and an adaptation of industry standards should be discussed.

Geochemical characterization of dust from arsenic-bearing tailings, Giant Mine, Canada

Dust from uncovered mine tailings at Giant mine, an abandoned mine in northern Canada, has been a concern for nearby residents. We have utilized microanalytical mineralogical analysis combined with quantitative measurements of phase distribution and bulk concentration to fully characterize the dust currently generated from the Giant mine tailings. Surface tailings material was sampled from three tailings impoundments on site and sieved to <63 μm as a proxy for dust, and total suspended particulate (TSP) samples were collected continuously over two months to represent the airborne material that is generated from the tailings. Inductively coupled plasma-optical emission spectrometry (ICP-OES) and -mass spectrometry (ICP-MS) show elevated concentrations of As, Sb, Zn, Pb, Cu and Ni in all samples; comparison of results for sieved and unsieved samples show that As is more concentrated in the <63 μm fraction of the tailings. The X-ray absorption near edge structure (XANES) results for the tailings indicate that the As in the samples is a mixture of As1−, As5+ and As3+. Scanning electron microscope-based mineral liberation analysis (SEM-MLA) results show that roaster-generated iron-oxides (i.e., maghemite), calcium-iron arsenate (i.e., yukonite), and arsenopyrite comprise the majority of the As-bearing particles in the surface tailings; of these three solid phases, calcium-iron arsenate poses the greatest risk to human health as it exhibits the highest relative bioaccessibility. A rare lead arsenate phase, which may be bioaccessible, was also detected in minor quantities in the surface tailings; this phase was identified as mimetite through μXRD analysis. Very little arsenic trioxide was found in the surface tailings samples, and no arsenic trioxide was found in the TSP samples; this is because the tailings that were exposed to arsenic trioxide-bearing roaster stack emissions during the 1950s and 1960s have been buried by more recent tailings. Soils near the Giant mine tailings have been found to contain arsenic trioxide from historic stack emissions, which indicates that the mine-impacted environmental media surrounding a tailings impoundment could in some cases pose a greater risk to environmental and human health than the tailings themselves.

Post-Depositional Alteration of Calcium Carbonate Phases in Archaeological Ceramics: Depletion and Redistribution Effects

The final stage in the life history of prehistoric pottery prior to archaeological recovery is usually the longest, and frequently the most dynamic. The remains of archaeological ceramics spend hundreds to thousands of years deposited within the upper layers of the earth’s crust where they encounter the same diagenetic environmental processes as the surrounding natural materials. Harsh conditions of subterranean environments induce physical stresses and chemical reactions, causing alterations of ceramic structure and composition. This is especially true of carbonate-rich ceramics, as carbonate phases are soluble when deposited within acidic environments. This paper examines common carbonate depletion and accretion effects of post-depositional environments on ancient ceramics from two rather different geological and archaeological contexts: Mesoamerica and the Mediterranean. Potters in both regions produce vessels with carbonate-rich materials—clays, calcite, limestone—that alter due to long exposure to low-pH sediments and continual water table fluctuations. Ceramic petrography is employed to identify traces of carbonate alterations within ceramic microstructure and to characterize fabrics. Elemental compositions of the same sherds are characterized through either scanning electron microscopy coupled with energy-dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry and optical emission spectrometry (ICP-MS/OES) or neutron activation analysis (NAA). This method enabled comparison of the differing effects of post-depositional alteration of carbonate phases on bulk composition signatures commonly used to determine provenance.

Source and Health Risk Assessment of PM2.5-Bound Metallic Elements in Road Dust in Zibo City

To study the pollution characteristics, sources, and ecological and health risk of PM2.5-bound metallic elements in road dust in Zibo City, a total of 97 dust samples were collected in eight districts between October 2016 and May 2017, and particles smaller than 2.5 μm were suspended filtered using a resuspension system. Inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES) were used to investigate 18 metal elements within the dust samples. The results showed that the mass fraction of Ca[ω(Ca)] was highest with an average of 120307.7 mg·kg-1, which was 7.2 times higher than the soil background values for Shandong Province. The mean values of ω(Zn), ω(Cu), ω(Sb), and ω(Cd) were 13.9, 11.7, 13.3, and 29.6 times higher than the background values, respectively. The geo-accumulation index (Igeo) indicated high levels of Cd, Zn, Cu, and Sb pollution, especially in winter. Enrichment factors (EFs) also indicated high concentrations of Cd, Zn, Sb, and Cu in the road dust, which were notably affected by human activities. Principal component analysis (PCA) showed that biomass combustion, coal burning, vehicle emissions, iron and steel smelting, and soil dust are the five main sources of metal elements in road dust in Zibo City. The potential ecological risk of Cd and the total potential risk were extremely high during three seasons and was highest in winter. Health risk assessment showed that As and Pb had a non-carcinogenic risk for children, while Cr presents a carcinogenic risk. In conclusion, pollution from PM2.5-bound metallic elements in road dust in Zibo City is derived from anthropogenic sources and is most severe during winter. Importantly, the levels of pollution detected represent potential ecological risk as well as some non-carcinogenic and carcinogenic risks for children. Therefore, the source control of road dust requires particular attention.

To incinerate or not? – Effects of incineration on the concentrations of heavy metals and leaching efficiency of post-precipitated sewage sludge (RAVITA™)

The major element and heavy metal concentrations of post-precipitated sewage sludge (PPS) and its ash residue (PPA) were determined using microwave digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS). To the best of our knowledge, this has not been previously done. In both PPS and PPA the heavy metal concentrations were clearly below the average concentrations than those encountered in sewage sludge in Europe. The leaching efficiency of the metal (Al/ Fe) used as a precipitation agent from post-precipitated sludge and its ash residue with phosphoric acid was also investigated with previously optimized leaching conditions. Tests resulted in leaching efficiencies for Al of 85 ± 1% and 99.5 ± 0.7% for PPS and PPA, respectively which were produced with aluminum as precipitation agent for phosphorus. Sludge, which was produced using iron as a precipitation agent, had a leaching efficiency of Fe 36.6 ± 0.9% and 68.0 ± 1.1%, for PPS and PPA, respectively. The leaching efficiency for P was 94 ± 3% and 96 ± 5% for Al-PPA and Fe-PPA, respectively.

Elemental analysis of commercial zirconia dental implants - Is “metal-free” devoid of metals?

ObjectivesThe interest in ceramic dental implants made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) or alumina toughened zirconia (ATZ) has increased in recent years. However, in the light of aging, corrosion, and potential impurities of zirconia ceramics, the material composition of these implants and the associated term “metal-free” is persistently questioned. Thus, the present study aimed to conduct an elemental analysis of commercial zirconia dental implants to specify their elemental composition and to identify contaminants. MethodsNine commercial zirconia dental implant systems and corresponding material samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). ResultsWhile the elemental composition was dominated by the main components Zr, Y and Al (in ATZ samples), all investigated samples contained impurities with Hf and contamination with alkali and alkali earth elements (Na, K, Mg, Ca), essential trace elements (e.g. Fe, Cu, Zn) but also potentially noxious metal elements (e.g. Ni, Cr). Furthermore, ultra-trace level contamination with the radionuclides U-238 and Th-232 was found in the majority of samples. SignificanceThe results indicate that, although all the investigated Y-TZP and ATZ dental implants meet the currently relevant ISO standards and manufacturer's specifications, from an elemental point of view, they are not devoid of metals. Due to the lack of a universal definition and thresholds for the term “metal-free”, the question of whether the examined zirconia dental implants can be holistically classified as “metal-free” or not remains a controversial, philosophical one.

P2O5-Free Cerium Containing Glasses: Bioactivity and Cytocompatibility Evaluation.

(1) Background: valuation of the bioactivity and cytocompatibility of P2O5-free and CeO2 doped glasses. (2) Methods: all glasses are based on the Kokubo (K) composition and prepared by a melting method. Doped glassed, K1.2, K3.6 and K5.3 contain 1.2, 3.6, and 5.3 mol% of CeO2. Bioactivity and cytotoxicity tests were carried out in simulated body fluid (SBF) solution and murine osteocyte (MLO-Y4) cell lines, respectively. Leaching of ions concentration in SBF was determined by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). The surface of the glasses were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. (3) Results: P2O5-free cerium doped glasses are proactive according to European directives. Cerium increases durability and retards, but does not inhibit, (Ca10(PO4)6(OH)2, HA) formation at higher cerium amounts (K3.6 and K5.3); however, cell proliferation increases with the amount of cerium especially evident for K5.3. (4) Conclusions: These results enforce the use of P2O5-free cerium doped bioactive glasses as a new class of biomaterials.

Toxic Effects of Particulate Matter Derived from Dust Samples Near the Dzhidinski Ore Processing Mill, Eastern Siberia, Russia.

Ambient particulate matter (PM) is associated with increased mortality and morbidity, an effect influenced by the metal components of the PM. We characterized five sediment samples obtained near a tungsten-molybdenum ore-processing complex in Zakamensk, Russia for elemental composition and PM toxicity with regard to pulmonary, vascular, and neurological outcomes. Elemental and trace metals analysis of complete sediment and PM10 (the respirable fraction, < 10µm mass mean aerodynamic diameter) were performed using inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS). Sediment samples and PM10 consisted largely of silicon and iron and silicon and sodium, respectively. Trace metals including manganese and uranium in the complete sediment, as well as copper and lead in the PM10 were observed. Notably, metal concentrations were approximately 10× higher in the PM10 than in the sediment. Exposure to 100µg of PM10 via oropharyngeal aspiration in C56BL/6 mice resulted in pulmonary inflammation across all groups. In addition, mice exposed to three of the five PM10 samples exhibited impaired endothelial-dependent relaxation, and correlative analysis revealed associations between pulmonary inflammation and levels of lead and cadmium. A tendency for elevated cortical ccl2 and Tnf-α mRNA expression was induced by all samples and significant upregulation was noted following exposure to PM10 samples Z3 and Z4, respectively. Cortical Nqo1 mRNA levels were significantly upregulated in mice exposed to PM10 Z2. In conclusion, pulmonary exposure to PM samples from the Zakamensk region sediments induced varied pulmonary and systemic effects that may be influenced by elemental PM composition. Further investigation is needed to pinpoint putative drivers of neurological outcomes.

Cytocompatibility of Potential Bioactive Cerium-Doped Glasses based on 45S5.

The cytocompatibility of potential bioactive cerium-containing (Ce3+/Ce4+) glasses is here investigated by preparing three different glasses with increasing amount of doping CeO2 (1.2, 3.6 and 5.3 mol% of CeO2, called BG_1.2, BG_3.6 and BG_5.3, respectively) based on 45S5 Bioglass® (called BG). These materials were characterized by Environmental Scanning Electron Microscopy (ESEM) and infrared spectroscopy (FTIR) after performing bioactivity tests in Dulbecco’s Modified Eagle Medium (DMEM) solution, and the ions released in solution were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Optical Emission Spectrometry (ICP-OES). The data obtained clearly show that the glass surfaces of BG, BG_1.2 and BG_3.6 were covered by hydroxyapatite (HA), while BG_5.3 favored the formation of a cerium phosphate crystal phase. The cytotoxicity tests were performed using both murine long bone osteocyte-like (MLO-Y4) and mouse embryonic fibroblast (NIH/3T3) cell lines. The cerium-containing bioactive glasses show an increment in cell viability with respect to BG, and at long times, no cell aggregation and deformation were observed. The proliferation of NIH/3T3 cells increased with the cerium content in the glasses; in particular, BG_3.6 and BG_5.3 showed a higher proliferation of cells than the negative control. These results highlight and enforce the proposal of cerium-doped bioactive glasses as a new class of biomaterials for hard-tissue applications.

Determinación de potenciales contaminantes inorgánicos en muestras de suelos y aguas del territorio uruguayo en la Antártida

Scientific research in Antarctica has increased in recent years, mainly in areas such as Microbiology, Biology and Oceanography. There are few reports about the levels of inorganic contaminants and the anthropic impact related to them in the ecosystem. Being a practically virgin territory, it is of particular interest to carry out this evaluation. In this work, for the first time and as a first approximation to the approach of the subject, six water samples and six soil samples obtained in six sampling points near the Uruguayan base in Antarctica were analyzed. The elements determined for both matrices were: chromium, nickel, cobalt, arsenic, strontium, cadmium, mercury, lead, uranium. In water, thorium, tin and antimony were also determined. The preparation of soil/sediment samples was carried out by means of an assisted treatment with microwave radiation; the water samples were analyzed directly. The analytical determinations were carried out by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). The majority of the elements are within the limits established by some environmental regulation agencies such as the Canadian Environmental Quality Guidelines-CCME or the United States Environmental Protection Agency-USEPA, being striking strontium content in waters.

Bioavailability of Metals at a Southeastern Brazilian Coastal Area of High Environmental Concern Under Anthropic Influence: Evaluation Using Transplanted Bivalves (Nodipecten nodosus) and the DGT Technique

Metals are commonly determined in aquatic organisms, primarily using bivalves to provide important data on their bioavailability. The technique of diffusive gradients in thin films (DGTs) has also been employed to assess the concentration of metals in freshwater and marine environments, determining their lability. The present work evaluated and compared the labile and bioavailable concentrations of Cd, Co, Cu, Mn, Ni and Pb in seawater from Ilha Grande Bay, RJ, using DGT and transplanted bivalves (Nodipecten nodosus), respectively. The scallops and DGTs were immersed in water at three sampling locations within the bay from July to September 2012 (winter campaign) and from December 2012 to February 2013 (summer campaign). The metals were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). DGT technique was successfully used to determine the concentrations of metals in waters, except for Pb when short deployment times were used. All metals were determined using transplanted bivalves (N. nodosus), but pre-exposure to Cd was evident, which made the interpretation of the data for this analyte difficult. The data on metal lability in Ilha Grande Bay waters obtained from the DGT technique were correlated with the metal bioavailability determined in the soft tissues of the transplanted N. nodosus for Co, Cu, Mn, Ni and Pb. This is the first evaluation of this type for this area of high environmental concern. Both techniques revealed that Nautico was the location with the highest concentration of metals in the study area.

Missions to Mars: Characterisation of Mars analogue rocks for the International Space Analogue Rockstore (ISAR)

Instruments for surface missions to extraterrestrial bodies should be cross-calibrated using a common suite of relevant materials. Such work is necessary to improve instrument performance and aids in the interpretation of in-situ measurements. At the CNRS campus in Orléans, the Observatoire des Sciences de l'Univers en région Centre (OSUC) has created a collection of well-characterised rocks and minerals for testing and calibrating instruments to be flown in space missions. The characteristics of the analogue materials are documented in an accompanying online database. In view of the recent and upcoming rover missions to Mars (NASA's 2011 Mars Science Laboratory (MSL) and ESA/Roscosmos' 2018 ExoMars), we are concentrating initially on materials of direct relevance to the red planet. The initial collection consists of 15 well-studied rock and mineral samples, including a variety of basalts (ultramafic, weathered, silicified, primitive), sediments (volcanic sands, chert, and a banded iron formation –BIF-), and the phyllosilicate nontronite (a clay). All the samples were characterised petrographically, petrologically, and geochemically using the types of analyses likely to be performed during in-situ missions, in particular ExoMars: hand specimen description; optical microscopy; mineralogical analysis by XRD, Raman and IR spectrometry; iron phase analysis by Mössbauer spectroscopy (MBS), elemental analysis by Energy-Dispersive X-ray spectroscopy (EDX), microprobe, Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and Mass Spectrometry (ICP-MS); and reduced carbon analysis by Raman spectrometry.

Chemical Elemental Distribution and Soil DNA Fingerprints Provide the Critical Evidence in Murder Case Investigation

BackgroundThe scientific contribution to the solution of crime cases, or throughout the consequent forensic trials, is a crucial aspect of the justice system. The possibility to extract meaningful information from trace amounts of samples, and to match and validate evidences with robust and unambiguous statistical tests, are the key points of such process. The present report is the authorized disclosure of an investigation, carried out by Attorney General appointment, on a murder case in northern Italy, which yielded the critical supporting evidence for the judicial trial.Methodology/Principal FindingsThe proportional distribution of 54 chemical elements and the bacterial community DNA fingerprints were used as signature markers to prove the similarity of two soil samples. The first soil was collected on the crime scene, along a corn field, while the second was found in trace amounts on the carpet of a car impounded from the main suspect in a distant location. The matching similarity of the two soils was proven by crossing the results of two independent techniques: a) elemental analysis via inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES) approaches, and b) amplified ribosomal DNA restriction analysis by gel electrophoresis (ARDRA).ConclusionsBesides introducing the novel application of these methods to forensic disciplines, the highly accurate level of resolution observed, opens new possibilities also in the fields of soil typing and tracking, historical analyses, geochemical surveys and global land mapping.

Multielemental Fingerprinting as a Tool for Authentication of Organic Wheat, Barley, Faba Bean, and Potato

The multielemental composition of organic and conventional winter wheat, spring barley, faba bean, and potato was analyzed with inductively coupled plasma-optical emission spectrometry (ICP-OES) and -mass spectrometry (ICP-MS). The crops were cultivated in two years at three geographically different field locations, each accommodating one conventional and two organic cropping systems. The conventional system produced the highest harvest yields for all crops except the nitrogen-fixing faba bean, whereas the dry matter content of each crop was similar across systems. No systematic differences between organic and conventional crops were found in the content of essential plant nutrients when statistically analyzed individually. However, chemometric analysis of multielemental fingerprints comprising up to 14 elements allowed discrimination. The discrimination power was further enhanced by analysis of up to 25 elements derived from semiquantitative ICP-MS. It is concluded that multielemental fingerprinting with semiquantitative ICP-MS and chemometrics has the potential to enable authentication of organic crops.

Evaluation of sample pretreatment methods for multiwalled and single-walled carbon nanotubes for the determination of metal impurities by ICPMS, ICPOES, and instrument neutron activation analysis

The manufacture of carbon nanotubes (CNTs) relies on the use of transition metal catalysts. The presence of metals in CNTs has been shown to critically affect the physical, chemical and surface properties of the material for applications in areas such as gas sensors and microcolumns. Once CNTs are released into the environment, the bioavailability of the metals is of concern, in the context of potential human toxicity. In the present study, methods were developed to determine the metals' concentrations in single-walled and multiwalled CNTs (SWCNT and MWCNT, respectively). The metals' concentrations in the SWCNT and MWCNT were determined by inductively coupled plasma optical emission spectrometry (ICPOES) and mass spectrometry (ICPMS), after the CNTs had been pretreated with one of the three extraction/digestion methods: water extraction, dilute acid (1% HNO3) extraction, and microwave acid digestion. The total metal concentrations were determined by instrumental neutron activation analysis (INAA). The metals in CNTs were found to have poor solubility in water and dilute acid, suggesting that the role of CNT metals in cytotoxicity may be limited due to their limited bioavailability, and that metals encapsulated in the CNTs could have potential use as tracers for CNTs, in biological or toxicological studies. Microwave acid digestion can achieve a near-complete extraction of metals from the CNTs, and thus is a suitable cleaning method, when high-purity CNTs are desired. Microwave acid digestion followed by ICPOES analysis produced results closer to those obtained by INAA than to those obtained by ICPMS; the latter method was subject to nonspectral interference induced by carbon residues in the sample solution.

Studies on the origin and transformation of selenium and its chemical species along the process of petroleum refining

Inductively coupled plasma optical emission spectrometry and mass spectrometry (ICPMS), the latter hyphenated to flow injection hydride generation, electrothermal vaporization or ion chromatography, have been applied to the chemical characterization of crude oil, aqueous process stream samples and wastewaters from a petroleum refinery, in order to get information on the behavior of selenium and its chemical species along effluent generation and treatment. Multielemental characterization of these effluents by ICPMS revealed a complex composition of most of them, with high salinity and potential spectral and non-spectral interferents present. For this reason, a critical re-assessment of the analytical techniques for the determination of total selenium and its species was performed. Methane was employed as gas in dynamic reaction cell ICPMS and cell parameters were optimized for a simulated brine matrix and for diluted aqueous solutions to match the expected process and treated wastewaters samples. The signal-to-background ratios for 78Se and 80Se were used as criteria in optimization, the first isotope resulting in better detection limits for the simulated brine matrix ( 78Se: 0.07 μg L − 1 , 80Se: 0.31 μg L − 1 ). A large variability in the concentration of selenium (from < 10 μg kg − 1 up to 960 μg kg − 1 ) was observed in 16 of the most frequently processed crude oil samples in the refinery here investigated, which may explain the pronounced concentrations changes of this element measured in aqueous process stream and wastewater samples. Highest concentrations of total selenium were analyzed in samples from the hydrotreater (up to about 1800 μg L − 1 ). The predominance of selenocyanate (SeCN −) was observed in most of the wastewaters so far investigated, but also other species were detected with retention times different from Se(IV), Se(VI) and SeCN −. Colloidal selenium (Se 0) was the only Se-species observed in samples from the atmospheric distillation unit, but was also identified in other samples, most probably formed by the decomposition of SeCN − or other unstable species.

Ulasitai: A new iron meteorite likely paired with Armanty (IIIE)

Abstract— The Ulasitai iron was recently found about 130 km southeast to the find site of the Armanty (Xinjiang, IIIE) meteorite. It is a coarse octahedrite with a kamacite bandwidth of 1.2 ± 0.2 (0.9–1.8) mm. Plessite is abundant, as is taenite, kamacite, cohenite, and schreibersite with various microstructures. Schreibersite is Ni‐rich (30.5–55.5 wt%) in plessite or coexisting with troilite and daubreelite, in comparison with the coarse laths (20.6–21.2 wt%) between the Widmanstätten pattern plates. The correlation between the center Ni content and the half bandwidth of taenite suggest a cooling rate of ˜20 °C/Myr based on simulations. The petrography and mineral chemistry of Ulasitai are similar to Armanty.The bulk samples of Ulasitai were measured, together with Armanty, Nandan (IIICD), and Mundrabilla (IIICD), by inductively coupled plasma atomic emission spectrometry (ICP‐AES) and mass spectrometry (ICP‐MS). The results agree with literature data of the same meteorites, and our analyses of four samples of Armanty (L1, L12, L16, L17) confirm a homogeneous composition (Wasson et al. 1988). The bulk composition of Ulasitai is identical to that of Armanty, both plotting within the IIIE field. We classify Ulasitai as a new IIIE iron and suggest that it pairs with Armanty.

Internal Standardization−Atomic Spectrometry and Geographical Pattern Recognition Techniques for the Multielement Analysis and Classification of Catalonian Red Wines

Major and minor (K, P, Ca, Mg, Na, Fe, Mn, Zn, and Sr) and trace (Ba, Ni, Pb, V, Co, Cd, and Sb) elements from wine samples from the Denomination of Origin (DO) Empordà-Costa Brava (Catalonia, Spain) were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and mass spectrometry (ICP-MS) respectively. Previously, a comparison of different calibration methodologies and sample digestion treatments had been carried out using ANOVA statistical tool. The obtained results demonstrated that internal standardization provides reliable results with the advantage that no further manipulation of the sample is needed. A principal component analysis of the concentration data was performed to differentiate the samples of DO Empordà-Costa Brava from wine samples from other wine-producing regions in Spain (i.e., Penedès, Somontano, and Rioja). It was found that Sr and Ba contents discriminate the two DO groups. Moreover, a discriminant analysis function involving both variables distinguishes the two groups with a 100% classification rate. At the level of the leave-one-out cross-validation, all of the Empordà-Costa Brava samples were well classified, whereas the other DOs presented two borderline misclassifications.