ICP-MS Results Research Articles

Compositional analysis of Silybum marianum plant at reduced pressure using calibration-free LIBS

Silybum marianum is an annual herb with a wide range of therapeutic values due to its high nutritional content. The compositional analysis of different parts of this plant, such as seeds and leaves, was performed using calibration-free laser-induced breakdown spectroscopy. The optical emission spectra from laser-generated plasma of seeds and leaves revealed the elemental profile, including Mg, Na, Ca, K, Si, Al, Zn, Rb, Sr, Fe, Ti, Ba, C, O, H, and N. The study was focused on improving LIBS based quantitative analysis by reducing self-absorption using two approaches.In the first approach, a theoretical model based on the internal reference line method and the relation between experimental and theoretical broadening was established to reduce self-absorption in the measured spectral line at atmospheric pressure. In the second approach, the self-absorption was evaluated at reduced pressure, which shows considerably reduced for most of the spectral lines at 10 mbar pressure. Thereafter, the theoretical model was applied at reduced pressure to further correct the line intensities. Finally, the self-absorption corrected line intensities were used for the compositional analysis of the plant using one-line CF-LIBS. The analytical results obtained with both approaches show that the results of the theoretical model at a reduced pressure are in close agreement with the ICP-MS results.

Iron powder in-situ catalytic pyrolysis on coated wooden board: Kinetic, products, and recovery

Catalytic pyrolysis is a promising method for the resource utilization of wooden waste, and in-situ catalysis enhances the process and reduces treatment costs. The selection of catalysts is crucial, as their catalytic effect and service life directly impact treatment effectiveness and economic benefits. In this study, iron powder was utilized to examine its potential in in-situ catalytic pyrolysis of coated wooden boards. The results showed that some of the iron powder could compete for oxygen from lignin/ hemicellulose during the early pyrolysis stage, resulting in the formation of FeO and a decrease in CO2. The formed FeO then promoted cellulose decomposition, reducing the pyrolysis activation energy by 26% ∼ 48%. Despite the addition of iron powder, no obvious impact was observed on the distribution of product yields. However, there are differences in the specific composition: the gas products showed a decrease of CO2 by 26% and CH4 by 13%, while the bio-oil showed an increase of phenol by 8%. This revealed that the iron powder primarily changed the energy barrier of the pyrolysis reaction. There was magnetic separation followed by particle size screening for the recovery of solid products. After separation, the recovery rate of iron powder was determined to be only 65.39%. Two kinds of char particles appeared in the separated products: magnetic (M3) and non-magnetic (NM). Approximately 44.45% of total Fe (from Fe powder and coating materials) contents and 73.62% of total Ti (main metal in the primary coating) were found in M3, while only 1.32% and 10.90% in NM, respectively. Interestingly, the distribution of elements Zn, Ba, and Mg was found to be opposite to that of Fe, which mainly distributed in NM and M2. It might be attributed to the primary coating on the M3 surface, which likely to help facilitated the adsorption of iron particles according to the combination of SEM/EDS and ICP-MS results. The adsorption competition effect of Fe and other metals resulted in significant differences in the distribution of metals on several char particles.

An efficient pretreatment method based on AgNPs-doped SnO2 photocatalyst for the accurate detection of heavy metals in organic-rich water samples

Humic acid (HA), the primary composition of natural organic matter (NOM) widely distributed in water and soil, can complex with heavy metal ions (HMIs), i.e., Cd(II) and Pb(II) in this study, which deters the accurate detection of HMIs using square wave anodic stripping voltammetry (SWASV). Hence, in this study, an efficient pretreatment method was proposed to restore the electrochemical signal of Cd(II) and Pb(II) by breaking the complexation based on AgNPs-doped SnO2 photocatalyst combined with LP/UV irradiation. Optimization of the key parameters for electrochemical signal restoration including pH for photolysis, AgNPs doping rate, photocatalyst dosage and photolysis time were performed to further elevating the accuracy in the proposed pretreatment method over 96.9% for Cd(II) and Pb(II) in 15 min. The effect of different HA concentrations on SWASV signal of Cd(II) and Pb(II) was also investigated adopting the optimal parameters. Then, the UV–vis absorption spectra, crystal structure, and the morphology of AgNPs-doped SnO2 photocatalyst were investigated to excavate the reasons behind the most excellent AgNPs doping rate to SnO2 in signal restoration. Moreover, the behavior of HA degradation and transformation under LP/UV irradiation was studied to investigate the mechanism of electrochemical signal restoration. Finally, the feasibility of the proposed method was testified by comparing detection results with ICP-MS results using real water samples extracted from aquaculture water.

Heavy metals high-sensitive detection by laser-induced breakdown spectroscopy based on radial electroosmotic flow-driven enrichment

Heavy metal detection is imperative for human health and environmental sustainability. However, the commonly used liquid sample pretreatment, drying liquid droplet to solid, encounters solute diffusion and nonuniform distribution, thus causing unpromising detection results. Here, we developed a radial electroosmotic flow-driven (REOF) platform to enrich heavy metals in water for high-sensitive detection using laser-induced breakdown spectroscopy (LIBS). Firstly, the electrodes in the substate for REOF were designed and produced by the printed circuit board manufacturer. Different particle deposition patterns were observed by modifying the direction and magnitude of voltage in the evaporated droplets of Cadmium Chloride (CdCl2) on the substrate. Then, the two-dimensional model of the evaporating droplets with REOF was established to verify the experimental phenomenon. The CdCl2 (10–50 mg/L) and Manganese Chloride (MnCl2, 1–8 mg/L) solutions were quantitatively analyzed with the optimized parameter on the substrate by LIBS. The detection limits of Ca and Mn can be reduced by approximately 42 times with REOF substrates by LIBS. Finally, the Mn in the real underground water sample was tested with the REOF substrate by LIBS, and the relative error was 5.5% compared with the results of ICP-MS. The results demonstrated that the REOF can enrich and uniformly distribute the solute on the substrate, and be helpful for the analysis of heavy metals in solution with LIBS.

Phytochemical fingerprint and biological activity of raw and heat-treated Ornithogalum umbellatum

The plants that we use as food in our daily diet and as risk preventers against many diseases have many biological and pharmacological activities. The heat treatments applied during the cooking of the plants cause changes in the phytochemical content and bioactivity. In this study, the phytochemical fingerprint and biological activities of raw and heat-treated extracts of Ornithogalum umbellatum L., which is widely consumed in the Black Sea region, were investigated. The bulb and leaf parts of the plant consumed as food were dried in an oven at 35 °C and then ground into powder. For heat treatment, the plant was boiled at 100 °C for 20 min. Differences in phytochemical contents of raw and heat-treated extracts were determined by ICP-MS, LC–MS/MS, and FTIR analysis. Biological activity was investigated with antiradical, antimicrobial, antimutagenic and antiproliferative activity tests. In this way, the effect of heat treatment on both the phytochemical content and biological activity of the O. umbellatum extract was determined. Gallic acid, procateuic acid and caffeic acid were found as the main compounds in the O. umbellatum extract, while the presence of procateuic aldehyde, vanillin and kaempferol in minor proportions was determined. There was a significant decrease in phenolic compound levels after heat treatment and gallic acid content decreased by 92.6%, procateuic acid content by 90% and caffeic acid content by 84.8%. Significant differences were detected in macro and micro element levels after heat treatment in ICP-MS results. While Cd, Ba and Zn levels of the raw extract increased; Na, Mg, K, Fe, U, Co levels decreased significantly. In FTIR spectrum, shifts and disappearances were observed in some of the vibrations and the emergence of new vibrations was also determined after heat treatment. Raw extract exhibited strong scavenging activity against H2O2 and DPPH and had a broad spectrum antimicrobial property. As a result of heat application, regressions were detected in antiradicalic, antibacterial and antifungal activities. Antimutagenic and antiproliferative activities were determined by the Allium test and a significant decrease in both activities and loss of activity against some chromosomal abnormalities were determined after heat treatment. While the antiproliferative activity of the raw extract was 20%, the activity of the heat-treated extract decreased to 7.6%. The raw extract showed the strongest antimutagenic effect with 69.8% against the unequal distribution of chromatin. Similarly, the antimutagenic activity of the extract, which reduced the bridges by 56.1%, decreased to 0.74% after heat treatment and almost lost its antimutagenic activity. The biological activities of raw O. umbellatum are closely related to the major compounds it contains, and the decrease in the levels of these compounds with the effect of heat was reflected in the activity. Studies investigating the phytochemical contents of plants are very important and the studies investigating biological activities related to phytochemical content are more remarkable. In this study, the phytochemical fingerprint of O. umbellatum was determined, its biological activities were related to the compounds it contained, and the biological activity was found to be heat sensitive.

Copper in airborne fine particulate matter (PM2.5) from urban sites causes the upregulation of pro-inflammatory cytokine IL-8 in human lung epithelial A549 cells.

Fine atmospheric particles, such as PM2.5, are strongly related to the onset and exacerbation of inflammatory responses leading to the development of respiratory and cardiovascular diseases. PM2.5 is a complex mixture of tiny particles with different properties (i.e., size, morphology, and chemical components). Moreover, the mechanism by which PM2.5 induces inflammatory responses has not been fully elucidated. Therefore, it is necessary to determine the composition of PM2.5 to identify the main factors causing PM2.5-associated inflammation and diseases. In the present study, we investigated PM2.5 from two sites (Fukue, a remote monitoring site, and Kawasaki, an urban monitoring site) with greatly different environments and PM2.5 compositions. The results of ICP-MS and EDX-SEM indicated that PM2.5 from Kawasaki contained more metals and significantly induced the expression of the pro-inflammatory cytokine gene IL-8 compared to the PM2.5 from Fukue. We also verified the increased secretion of IL-8 protein from exposure to PM2.5 from Kawasaki. We further investigated their effects on inflammatory response and cytotoxicity using metal nanoparticles (Cu, Zn, and Ni) and ions and found that the Cu nanoparticles caused a dose-dependent increase in IL-8 expression together with significant cell death. We also found that Cu nanoparticles enhanced the secretion of IL-8 protein. These results suggest that Cu in PM2.5 is involved in lung inflammation.

Fluid origin and critical ore-forming processes for the giant gold mineralization in the Jiaodong Peninsula, China: Constraints from in situ elemental and oxygen isotopic compositions of quartz and LA–ICP–MS analysis of fluid inclusions

The Jiaodong Peninsula, China, is one of the largest gold provinces in the world. During a short time interval in the Early Cretaceous, over 5000 t of gold were accumulated there. The mechanisms controlling the focused Au deposition and the origins of massive amounts of auriferous fluids are still controversial. Quartz–sulfide lode mineralization (Linglong-type) and disseminated/stockwork mineralization (Jiaojia-type) are the two major mineralization styles in the Jiaodong Peninsula. Herein, we conducted in situ textural, elemental and oxygen isotopic analyses using scanning electron microscopy (SEM), laser ablation-inductively coupled plasma-mass spectrometry (LA–ICP–MS) and secondary ion mass spectrometry (SIMS) on quartz from different hydrothermal stages and depths for three representative Linglong-type (Linglong deposit) and Jiaojia-type (Xiadian and Jiangjiayao deposits) gold deposits in the northwestern Jiaodong Peninsula, with the aim to constrain the ore-forming processes. The LA–ICP–MS analysis of individual fluid inclusions was also conducted to unravel the origin of the auriferous fluids. The results show that from the pre-mineralization to the ore-forming stages in the Linglong-type mineralization, the homogenization temperatures and salinities of fluid inclusions and the δ18Oquartz values change slightly, but the Al concentrations of quartz decrease continuously. Combined with the coexistence of CO2- and H2O-rich fluid inclusion endmembers, these trends indicate the increase of pH induced by CO2 degassing (fluid–fluid unmixing), which led to focused Au deposition. The quartz grains from the Jiaojia-type mineralization typically show a homogeneous texture with well-correlated lithophile elements (e.g., K, Al and Rb), which are distinct from those of the Linglong-type that are characterized by oscillatory zoning with much higher Al concentrations and δ18Oquartz values. These phenomena indicate that enhanced fluid–rock interaction occurred in the Jiaojia-type mineralization. In addition, the δ18Oquartz values show an increase from deep to shallow depths. In combination with thermodynamic modelling, it suggests decreasing fluid–rock interaction with decreasing depth. The above results corroborate that multiple mechanisms led to the efficient Au deposition in the Jiaodong Peninsula. Fluid–fluid unmixing typically occurred in the Linglong-type mineralization, while fluid–rock interaction was dominant in the Jiaojia-type mineralization. The different mechanisms might render mining challenging due to the changeable locations of favorable Au unloading.The LA–ICP–MS results of fluid inclusions suggest that the ore-forming fluids are metamorphic fluids rather than magmatic–hydrothermal fluids. In combination with the isotopic compositions of ores showing considerable mantle affinities and large-scale mafic underplating occurring beneath the study region, we propose a new genetic model that accounts for the origin of the auriferous fluids. The new model invokes the devolatilization of previously emplaced H2O- and Au-rich amphibole cumulates through amphibolite- to granulite-facies metamorphism in the middle–lower crust. It suggests an alternative way to generate the ‘orogenic-like’ gold deposits.

Effects of imbalance of mineral elements on peripheral neutrophil metabolism in sheep

The imbalance of mineral element homeostasis in animals is common, causing animal immune dysfunction. Ten female sheep were randomly selected and injected with 4% (w/v) Na2EDTA through a central venous catheter to establish the mineral element imbalance model, then divided into control group (before injection) and Ethylene Diamine Tetraacetic Acid (EDTA) group (after injection). Isolation of peripheral blood neutrophils for mineral elements content determination was done using Inductively coupled plasma-mass spectrometry (ICP-MS) and nontargeted metabolomics analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The ICP-MS results showed that Hg and Cs levels in neutrophils were significantly lower after injection than before (P<0.05), but had no significant effects on other elements. Our previous study showed that serum Zn, P, K, and other 11 elements were significantly lower after the injection of Na2EDTA than before. LC-MS/MS results showed that differential metabolites are mainly involved in amino acid metabolism, lipid metabolism, and nucleotide metabolism; monoamine metabolism was weakened; and polyamine metabolism was enhanced. Under positive and negative ion modes, the mineral elements P, K, Ca, Mn, Cu, and Zn had the highest correlation with the differential metabolites of neutrophils, followed by Se, and the correlation between each mineral element and different differential metabolites was also different. The results indicated that the imbalance in mineral elements affected the metabolism of sheep neutrophils, these may affect neutrophil function, and Na2EDTA could help to reduce the level of heavy metals in the body of sheep. Our data may provide a theoretical basis for the precise regulation of animal immune metabolism by modern animal husbandry nutrition.

Environmental Geochemistry and Bioavailability and Health Effects of Chromium in Topsoil and Cauliflower Plant in Kirkuk, Northern Iraq

The content of chromium in the surface soil as well as its content in cauliflower plants in Kirkuk was studied to investigate the environmental geochemistry of this element. 30 samples of surface soil were collected from inside the study area at a depth of 0-20 cm. Eight samples of cauliflower were collected from the same study area, soil and plant sampling sites were determined using a GPS device . Using ICP-MS technology we were able to analyze these samples. The results of ICP-MS showed that the average concentration of chromium in the soil samples was 78.59 mg/kg and its highest concentration was in the sample A12 (93.4 mg/kg), the increase in the concentration of chromium in the soil is due to agricultural fertilizers, irrigation with sewage water, the impact of traffic, commercial activities and industrial workshop. The mean of its concentration cauliflower samples was 3.81 mg/kg, and the highest concentration was 4.7 mg/kg in sample AQ10, the increase in the concentration of chromium in the plant is due to pollution in the soil, and the difference in these concentrations is due to the location of the sample and the properties of the soil. The plant absorbs it through the roots, then the stems, leaves,and fruits. Bioaccumulation factor value for chromium ranged with an average of 0.047 for all cauliflower samples. CF soil samples that the surface soil for this area is within a level (low pollution, CF &lt;1) indicating the presence of pollution at a very low level, and the potential ecological risk index PRI found that all surface soil samples in the study area have (low risk level, PLI≤50), and Igeo indicates that there is no pollution (practically uncontaminated, Igeo ≤ 0). It was found that the value of THQnc for both groups of adults and children in the study area was greater than 1. The CRcancer values for both groups were greater than 1*10-4.

A polyrutin/AgNPs coated GCE for simultaneous anodic stripping voltammetric determination of Pb(II) and Cd(II)ions in environmental samples

Here, we report a simple one-step preparation of polyrutin/silver nanoparticles (AgNPs) on the glassy carbon electrode (GCE) surface using an electrochemical deposition/polymerization technique. As prepared polyrutin/AgNPs/GCE has been characterized by different techniques such as SEM with elemental morphing, TEM with EDAX, XRD, ATR-IR to confirm the materials formation. Further, electrochemical behavior of the polyrutin/AgNPs/GCE was tested by cyclic voltammetry, EIS and differential pulse voltammetric techniques. As fabricated polyrutin/AgNPs/GCE was used for simultaneous detection of Pb(II) and Cd(II)ions using anodic stripping voltammetric techniques and stripping analysis of Pb(II) and Cd(II)ions analytical parameters like pH, preconcentration time were studied. The polyrutin/AgNPs/GCE has showed a linear concentration range from 29 nM to 140 nM and 57–203 nM with detection limit of 3 nM and 10 nM for Pb(II) Cd(II)ions respectively. Further, the modified electrode was tested towards detection of these heavy metal ions in different environmental samples and the found excellent recovery results were further correlated with ICP-MS results.

Using Portable X-ray Fluorescence Spectroscopy for Inexpensive and Quick Determination of Micronutrients in Barley Shoots

ABSTRACT Determination of elemental concentrations in plant tissue samples is critically important for analyzing their nutritional content. Micro-elemental analysis mostly relies on inductively coupled plasma (ICP) spectrometry techniques, which are expensive, time-consuming, laborious, and complicated. Portable X-ray fluorescence (pXRF) spectroscopy is widely applied in earth sciences but is rarely practiced to quantify elements in plant samples. In this pilot study, the reliability of pXRF results was compared with that of ICP-mass spectrometer (MS) to determine concentrations of four micronutrients zinc (Zn), iron (Fe), copper (Cu), and cadmium (Cd) in barley (Hordeum vulgare L.) shoot samples. Ground barley samples were scanned with the pXRF instrument. The concentrations of Zn recorded using this method correlated well with the ICP-MS results (R 2 = 0.80), while Fe and Cu concentrations showed moderate correlations (R 2 = 0.57 and 0.42, respectively). However, no significant correlation was found between ICP-MS- and pXRF-derived concentrations for Cd (p > .05). This work demonstrated the potential of pXRF as a reliable and cost-effective alternative to ICP methods for determining Zn in plant samples as it allows the analysis of a greater number of samples in a short period at considerably less expense.

Characterization, Concentration of Biochar and Titanspheres and Heavy Metals Assessment of Quercus Suber Cork Powder Fly Ash Fractions

Cork powder is categorized in the group of the biodegradable fraction of products and waste. In Portugal, the cork powder production ranges between 32 000 and 37 000 tons/year and is used as fuel, which generates ash. For this ash characterization and possible recycling, sieving (dry and wet) and pre-treatments (ultrasounds and polycarboxylate) were tested in order to concentrate biochar, titanspheres and assess the fractions more suitable for fertilizer material. The samples were characterized via a combination of techniques: SEM/EDS, RLM, XRF, MRS and ICP-MS. For size-fractionation of cork powder fly ash, dry sieving is not an efficient method, however, improved efficiency, especially in the &lt;25 μm size-fraction, can be attained by preceding wet sieving with a combined pre-treatment of ultrasounds and polycarboxylate. A sequence method was applied for biochar concentration and purification, however the amount of final biochar obtained is very low (1%wt.). The ICP-MS results indicate that the use of cork powder ash as fertilizer material in plant crops intended for human and animal consumption is not recommended, whereas other uses in soils are possible.

Recent advances in stable isotope ratio analysis of common explosives

炸药的深度比对与溯源对于爆炸案事件的侦破具有重大意义,以不同地域来源的原料或不同生产工艺生产的炸药,其组成元素的稳定同位素比值具有差异,因而稳定同位素比值可作为炸药深度比对与溯源的重要指标。稳定同位素比值质谱法(IRMS)作为一种高精度的稳定同位素比值测量手段,已逐渐发展成熟,与元素分析仪、气相色谱仪、液相色谱仪等仪器联用,在食品安全、环境保护、法庭科学等领域应用广泛。IRMS在炸药比对与溯源上亦发挥了重要作用,自1975年IRMS被应用于区分不同国家生产的三硝基甲苯(TNT)以来,IRMS已成功用于多种炸药的分析。但目前尚未见有文献系统地总结常见炸药的稳定同位素比值分析研究进展。该文介绍了稳定同位素比值分析的相关原理、仪器组成及特点,分别总结了硝酸铵、黑火药、TNT、太恩、黑索金等常见炸药的稳定同位素比值分析方法,汇总了文献报道的不同国家生产的硝酸铵、黑火药、TNT等炸药的稳定同位素比值。文章就不同炸药的稳定同位素比值差异、炸药生产、存储过程中相关因素对同位素比值的影响,爆炸前后稳定同位素比值的变化情况等内容进行了分析。本文还指出了目前炸药的稳定同位素比值分析研究中存在的问题,对可能的解决办法进行了讨论,对未来的发展方向提出了建议。

Morphology, Mineralogy, and Chemistry of Atmospheric Aerosols Nearby an Active Mining Area: Aljustrel Mine (SW Portugal)

Mining activities increase contaminant levels in the environment, so it is crucial to study the particulate matter in these areas to understand the impacts on nearby urban areas and populations. This work was conducted close to the active mine of Aljustrel (Portugal), where black dust deposition is evident. PM10 samples were collected in two periods: 10–17 July and 1–10 November of 2018. Two different techniques were used: SEM-EDX for the individual characterization of the aerosols and ICP-MS to quantify the elemental concentration of 11 elements (Ca, Na, Fe, Mn, As, Cd, Cu, Sb, Pb, and Zn). In this region, the observed PM10 mass concentration was 20 to 47 µg m −3 (July) and 4 to 23 µg m−3 (November), which is lower than the limit of 50 μg m−3 established in the European Directive. The individual characterization of 2006 particles by SEM-EDX shows oxides (17%) and sulfides (10%), while Na, Si, Fe, S, Al, and Cu are the elements with the most representativeness in all the analyzed particles. The ICP-MS results indicate that the daily elemental concentration in the samples collected in July is higher than November, and only As exceeds the limit established for European legislation.

Mineral-geochemical characteristics Cu-U-Au-manifestations in the Kon Ra region of the Kon Tum province, Vietnam

Background. Complex Au-Cu-U mineralization is found in the metamorphic rocks of central Vietnam in the zones of their contact with Triassic granite intrusions. It is localized in tectonic breccias and cataclasites, which affected Triassic granitoids and Precambrian metaskarn rocks. The greatest differentiation is observed for tectonically disturbed granites of the Hai Van complex and the metasomatically reworked zones of contacts of this complex with metacarbonate and metaultramafic rocks of the Kham Duc complex.Aim. To determine the mineral and elemental composition of complex occurrences of Cu, U and Au in Proterozoic rocks of the Kon Tum province of central Vietnam.Materials and methods. The work was based on the authors’ data obtained during fieldwork and analytical laboratory studies in the 2016–2019 period. The diagnostics of ore mineral composition was carried out using 60 polished sections. The chemical composition of ores was determined for 214 samples by ICP MS and for 374 samples by atomic absorption spectrometry at the Vietnamese Centre for Geological and Experimental Analysis in the city of Hanoi. The geochemical relationships of ore components were established by the method of multivariate statistical correlations.Results. The mineral composition includes pyrrhotite, pyrite, chalcopyrite, molybdenite, magnetite, martite, hematite, cubanite, marcasite, gold, xenotime, sphalerite, uraninite, chalcocite, covellite, goethite, malachite and limonite. According to the petrographic and petrochemical composition, the geological position and the data on isotopic age, the metamorphic formations of the Kham Duc complex can be considered as Neoproterozoic-Cambrian formations having experienced metamorphism in the Ordovician.Conclusion. A scheme of the sequence of mineral formation was outlined. ICP MS results of primary ores showed that, in addition to Cu, the formations under study contain concentrations of Co, Mo, U, Au, Zn, Ni, V, Y, La, and As. A positive correlation was found between Cu, U and Au. A model of hydrothermal ore formation was proposed.

Iron isotope geochemistry and mineralogy of jarosite in sulfur-rich sediments

Jarosite is a common mineral in acidic, sulfate-rich environments where it is critical in regulating the acidity of aquatic systems and the mobility of trace elements and potential contaminants. This research aims to understand jarosite formation and recrystallization in these environments by examining the stable iron isotope geochemistry of jarosite at two coastal sites in Victoria, Australia: Fossil Beach and Southside Beach. Jarosite occurs at high abundance as beds, veins, surface coatings and nodules within oxidized zones of sulfidic sediment outcrops and as pebbles, cobbles, and boulders at the base of the outcrops within the intertidal zone, making these two beaches ideal natural laboratories. Synchrotron powder X-ray diffraction (XRD) and ICP-MS results indicate that samples are comprised predominantly of natrojarosite, often with substantial K substitution. Rietveld refinement of XRD patterns shows that most jarosite samples are a solid-solution of Na-K jarosite, differing from previous observations that (near-)end-member mixing predominantly occurs in nature. The iron isotope composition of the jarosite samples have δ56Fe values between −1.91 and +1.24‰ (relative to IRMM-014), an exceptionally large range that partially overlaps with the δ56Fe values of the sulfidic sediment precursor (−0.54 to +1.30‰). There is a negative relationship between the alkali ratio [Na/(Na + K)] and iron isotope composition, with the heavier iron isotopes preferentially partitioned into K-rich jarosite. The large range in δ56Fe values of jarosite likely results from a combination of the variable δ56Fe values of the precursor sulfides, thermodynamic differences between Na- versus K-bearing jarosite, and an open-system Rayleigh distillation during jarosite formation.

Analysis of Silver and Gold Samples from the Borodino Treasure by Inductively Coupled Plasma Mass Spectrometry and Inductively Coupled Plasma Atomic Emission Spectrometry

One of the main requirements for the methods of elemental analysis of unique archaeological samples is to minimize the damage they cause. Two new procedures for analyzing silver and gold samples, weighing several milligrams, obtained by drilling from the inner surface of silver and gold artifacts of the Borodino treasure, stored in the State Historical Museum, are described. The procedures are based on the autoclave decomposition of samples and subsequent analysis of the obtained solutions by inductively coupled plasma mass spectrometry(ICP–MS) and inductively coupled plasma atomic emission spectrometry (ICP–AES). They enable the determination of more than 60 impurity elements in each sample with a determination limits from 1 × 10–2 to n × 10–3 wt % for common elements (Na, Mg, Al, K, Ca, Ti, and Fe) and to n × 10–7 wt % for REEs, Ir, Tl, and U. The correctness of the developed procedures is confirmed by the analysis of standard samples and by comparison with the ICP–MS results obtained with laser sampling, which allows direct analysis of samples without their dissolution.

Probe technique-based generalized multivariate standard addition strategy for the analysis of fluorescence signals with matrix effects

The presence of practically unavoidable matrix effects from the spectroscopically inactive compounds (which may enhance or suppress intensities of spectral measurements of samples) and background interference effects from the spectroscopically active compounds other than the analytes of interest in real-world complex samples can significantly affect the accuracy of quantitative results of optical chem/biosensing techniques, and hence greatly hinder their applications to real-world complex samples. In this contribution, a probe technique-based generalized multivariate standard addition strategy was designed for the analysis of fluorescence signals with both matrix effects and background interference effects. The performance of the proposed strategy was tested on a proof-of-concept system of quantifying Zn2+ in real-world samples such as rice and zinc gluconate oral solution using a selective fluorescence probe dansylaminoethyl-cyclen and compared with the classical univariate standard addition method. Experimental results demonstrated that one standard addition sample was enough for the proposed strategy to provide satisfactory quantitative results (consistent with the results of ICP-MS) for Zn2+ in the real test samples, which were by far better than the corresponding results of the classical univariate standard addition method. The main contributions of this research are 1) to greatly improve the accuracy of quantitative results of optical chem/biosensing techniques, and 2) to open up an avenue for quantitative analysis of small-volume biological samples or some precious samples using invasive techniques in fields such as biomedical sciences, clinical diagnosis and archeology, etc.

Determination of trace elements in calcium rich carbonate rocks by Wavelength Dispersive X-ray Fluorescence Spectrometry for environmental and geological studies

A simple, rapid and non destructive Wavelength Dispersive X-ray Fluorescence Spectrometry (WDXRFS) was developed for the determination of trace elements such as V, Cr, Co, Ni, Cu, Zn, Pb, Ba, La, Ce, Nd, Rb, Sr, Y, Zr, and Nb in carbonate rocks with high calcium content. Samples of marble, limestone, fluorite ore and carbonatite-like rocks were chosen as objects under investigation. These samples have wide ranges of major and trace element contents, and high concentration of calcite (70–98%) in calcium rich carbonates. The sample mass required for infinite thickness was calculated for each element. In order to determine V, Cr, Co, Ni, Cu, Zn, Ba, La, Nd, Ce, sample weighting 1g was pressed with a pressure of 100kN. For the determination of Rb, Sr, Y, Zr, Nb, Pb, the sample mass was increased up to 5g. The calibration curves were constructed by employing the International Certified reference materials (ICRMs) and in-house standard reference materials (HSRMs) of various types of rocks and sediments, and the matrix effects were taken into account using the influence coefficients (α-correction equations). Analytical figures of merit have also been assessed. The calculated values of the instrumental limit of the detection were within the interval from 0.5 to 4.0mgkg−1. The repeatability and reproducibility were found to be satisfactory with the relative standard deviations lower than 5%. The accuracy was evaluated by the analysis of two reference materials and the comparison with the ICP-MS results. A good agreement was achieved between the reference and measured values with recoveries ranging from 85% to 115%. The relative disagreements between the XRF and ICP-MS results were less than 10%.

ASSESSMENT OF ANTHROPIC SOURCES THROUGH PB ISOTOPES IN SÃO DOMINGOS BASIN, RIO DE JANEIRO, BRAZIL

Sediments from Sao Domingos Basin were analyzed for Pb isotope composition aiming to characterize the contamination by metals, in an area of tomato production with intense use of pesticide. Located in the city of Sao Jose de Uba, Rio de Janeiro State, Brazil, an important tomato producer, that basin is an environmental laboratory due to the crop activity. This work aims to trace the anthropic activity in the basin using Pb isotope composition and comparing the results with other similar works. Sampling was carried out using stream 23 bottom sediments samples. The 200 mesh (0.075 mm) fraction was leached (using HNO 3 ) and residues were dissolved by HF. Samples were analyzed by two different mass spectrometer methods: leaching in ICP-MS, and leaching and residue in TIMS. For TIMS analysis, Pb was separated by ion exchange columns. The results define Pb/Pb isotope signature groups interpreted as different sources of Pb. The samples analyses yielded different Pb compositions, probably resulting from active pollutants which were transported by the rivers and provided by mixed sources. The 206 Pb/ 207 Pb ratios, applied in environmental studies, are used to trace pollution sources in this work. The results of ICP-MS and TIMS show 206 Pb/ 207 Pb values from 1.093 to 1.333 from leaching and 1.143 to 1.490 from residues. Each method has results that can be separated in two groups. The values from the first group are associated with gasoline and geogenic (Ribeira Belt Neoproterozoic rocks) sources and have the highest Pb concentration. The values of the second group may be interpreted as sewage and unidentified source, probably related to the pesticide used in the tomato crops, and have the lowest Pb concentration. Hence, gasoline and natural source are the main metal contributions. Both methods show similar values and complete each other; however, TIMS shows better precision than ICP-MS.