Quantitative Analysis Of Metals Research Articles

The analysis of e-liquids: A study on chemical diversity and metal content using gas chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry.

This work aimed to determine the chemical composition of 22 e-liquids available on the Slovenian market. Four different gas chromatography (GC) sample introduction techniques; headspace-GC-mass spectrometry (HS-GC-MS), liquid injection-GC-MS (LI-GC-MS), HS-solid-phase microextraction-GC-MS (HS-SPME-GC-MS), and direct-immersion-SPME-GC-MS (DI-SPME-GC-MS) were employed for qualitative analysis. Various experimental parameters were assessed for each GC sample introduction technique to maximize compound identification. Despite e-liquid packaging reporting a maximum of eight compounds, GC-MS identified more compounds in most samples, especially in menthol-flavored (58 identifiable compounds by HS-SPME-GC-MS), followed by nicotine-containing and fruit-flavored samples. HS-SPME-GC-MS identified the highest number of compounds, followed by HS-GC-MS, DI-SPME-GC-MS, and LI-GC-MS. Nicotine quantification in six samples was performed by LI-GC-MS with dilution in methanol. Nicotine concentration in samples ranged from 16.5±0.5 to 18.5±0.4 mg/mL, which was below the declared concentration of 20mg/mL. Additionally, quantitative analysis of metals in e-liquids was performed by inductively coupled plasma-MS after microwave-assisted wet acid digestion. Iron was the most abundant metal, with its content ranging from 0.024 to 0.354µg/g. Barium, bismuth, copper, and tin were also determined in several e-liquids.

Synthesis of NaYF4:Yb3+, Tm3+ Nanocrystals Via the Thermal Decomposition Method Using Refined Sunflower Oil

Abstract In recent years, up-conversion luminescence nanoparticles have attracted significant attention from researchers in fields such as analytical chemistry (for example qualitative and quantitative analysis of metal and non-metal ions) and biomedicine (cancer imaging, drug delivery, treatment, etc.) due to their high rate of emission efficiency, easy surface functionalization, great chemical and thermal and photostability and other favorable properties. NaYF4 in particular has attracted interest of researchers as a host material due to its low phonon energy, thus increasing the efficiency of emission. In this study, the synthesis of NaYF4:Yb3+,Tm3+ nanocrystals using the hydrothermal method was successfully carried out. Refined sunflower oil containing oleic acid was used as a solvent instead of analytical grade oleic acid and octadecene-1, reducing the cost of the synthesis. Using semi-quantitative XRD measurement analysis, it was determined that 25.3 % hexagonal β-NaYF4:Yb3+,Tm3+ as well as 23.8 % cubic α-NaYF4 nanocrystal crystalline phases were found in the synthesized sample. The sample showed mainly luminescent characteristics typical of hexagonal NaYF4:Yb3+,Tm3+ lattice nanoparticles.

Soil quality indices for metal(loid) contamination: An enzymatic perspective

AbstractSoil degradation by metal and metalloid (metal[loid]) contamination represents a widespread environmental threat. Most studies investigating soil metal(loid) contamination have disregarded the soil quality concept. Enzyme activities (EAs) are good soil quality indicators due to their direct connection to functions related to C, N, P, and S cycles and their sensitivity to metal(loid) contamination. This review (a) provides an overview of the development of soil quality indices (SQIs) based on EAs in metal(loid) contaminated soils, and (b) evaluates the effects of individual metal(loid)s and their combinations on the activities of the most common enzymes involved in the C, N, P, and S cycles. Four intracellular mechanisms dominate the inhibition of EAs by metal(loid)s: (a) transcription inhibition, (b) protein denaturation, (c) cell division inhibition, (d) cell membrane disruption. These mechanisms can also be further exacerbated in soil by nonspecific exoenzyme inhibition. The main EAs used as indicators for metal(loid) contaminated soils are dehydrogenase (DHA), arylsulfatase (ARY), urease (UA), acid phosphatase (Pacid), alkaline phosphatase (Palk), and catalase (CAT). These enzymes are sensitive to metal(loid) contamination, with DHA and ARY being the most sensitive indicators (62 and 56% inhibition, respectively, when averaged over all metal[loid] contamination levels). Other enzymes are inhibited by 32% (UA), 23% (Palk), 18% (Pacid), and 18% (CAT). We suggest principles for the development of SQIs considering biotic soil functions via the use of EAs. This review is the first presenting SQIs based on EAs for metal(loid) contaminated soils, and represents the first quantitative analysis of metal(loid) effects on EAs.

Extracellular DNA controls expression of Pseudomonas aeruginosa genes involved in nutrient utilization, metal homeostasis, acid pH tolerance and virulence.

Introduction. Pseudomonas aeruginosa grows in extracellular DNA (eDNA)-enriched biofilms and infection sites. eDNA is generally considered to be a structural biofilm polymer required for aggregation and biofilm maturation. In addition, eDNA can sequester divalent metal cations, acidify growth media and serve as a nutrient source.Aim. We wanted to determine the genome-wide influence on the transcriptome of planktonic P. aeruginosa PAO1 grown in the presence of eDNA.Methodology. RNA-seq analysis was performed to determine the genome-wide effects on gene expression of PAO1 grown with eDNA. Transcriptional lux fusions were used to confirm eDNA regulation and to validate phenotypes associated with growth in eDNA.Results. The transcriptome of eDNA-regulated genes included 89 induced and 76 repressed genes (FDR<0.05). A large number of eDNA-induced genes appear to be involved in utilizing DNA as a nutrient. Several eDNA-induced genes are also induced by acidic pH 5.5, and eDNA/acidic pH promoted an acid tolerance response in P. aeruginosa. The cyoABCDE terminal oxidase is induced by both eDNA and pH 5.5, and contributed to the acid tolerance phenotype. Quantitative metal analysis confirmed that DNA binds to diverse metals, which helps explain why many genes involved in a general uptake of metals were controlled by eDNA. Growth in the presence of eDNA also promoted intracellular bacterial survival and influenced virulence in the acute infection model of fruit flies.Conclusion. The diverse functions of the eDNA-regulated genes underscore the important role of this extracellular polymer in promoting antibiotic resistance, virulence, acid tolerance and nutrient utilization; phenotypes that contribute to long-term survival.

Quantitative analysis of metals and metal-based nano- and submicron-particles in tattoo inks.

Exposure to metals and metal-based nano- (NPs, 1-100nm) and submicron-particles (SPs, 0.1-1μm) contained in tattoo inks and related health safety is currently receiving a great deal of interest. Twenty inks of different brands and colours were sampled in Italy in 2019. The SemiQuant Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis allowed quantifying the concentration of 18 metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, Ti, Zn) in inks. The Single Particle ICP-MS was used to detect the diameters and concentration of NPs and SPs of 9 metals (Al, Co, Cr, Cu, Hg, Ni, Pb, Ti and Zn). Concentration of metals in tattoo inks were below the recommended concentrations reported in the Resolution ResAP (2008)1 indicating ink production have shifted to purer materials and best manufacturing practices. Regarding particles, Al was found at nano- (62-80nm) and submicron-sizes (105-140nm). Sizes of Cr, Cu, Pb and Zn were in the intervals 42-62nm, 44-96nm, 26-28nm and 26-59nm, respectively. Titanium was at submicron-diameters (166-383nm). In addition, Cr and Ti particles accounted for the 47% and 80% of their total concentration, respectively. Tattooing practice exposed humans to metal-based NPs and SPs and the presence of a combination of particles of different metals and/or their dynamics (e.g., dissolution) may change their bioavailability and toxicity.

Partial least squares regression calculation for quantitative analysis of metals submerged in water measured using laser-induced breakdown spectroscopy.

Effects of different parameters regarding partial least squares (PLS) regression analysis are investigated for quantitative analysis of water-submerged brass samples. The concentrations of Cu and Zn in various brass alloys were quantified using PLS, and the performance after different signal processing steps (normalization, smoothing, and background subtraction) and database segmentation by excitation temperature is compared. In addition, the effects of averaging numbers on the results are examined. From the results, normalization was found to be the most effective among three established signal processing methods. The effects of both peak and background fluctuations seen in the signals are reduced by normalization. It was found that temperature segmentation of the database in an appropriate range, which should be high enough for reliable peak detection, can further improve the accuracy of PLS calculations. The proposed method is applicable in real time, and can potentially be used for automated fast and accurate measurements of solids at oceanic pressures.

Laser-induced breakdown spectroscopy for the quantitative analysis of metals in sediments using natural zeolite matrix

The dependence of laser-induced breakdown spectroscopy (LIBS) to the matrix of the sample remains an important consideration in performing quantitative analysis. In this study, a new matrix was introduced in the preparation of solid powder calibration curves. Heat-treated natural zeolite and KBr were mixed separately into high purity metal powders to generate calibration curves using a univariate approach. A LIBS technique was used in the detection and quantitative analysis of Cr, Cu and Pb in river sediment samples. The relative percent difference (RPD) was calculated to describe the variability measurements made using ICP/OES and LIBS as well as to evaluate the accuracy of the method. Calculated limits of detection in the matrices prepared were comparable with literature values and ranged from 0.41 to 6.1ppm. The resulting metal concentrations indicate that the natural zeolite matrix were closer to the reference values compared to the KBr matrix. By employing principal component analysis (PCA), heat treated zeolite was shown as a potential diluent or binder for generating calibration curves and could provide matrix-matched standards in identification of target metals from unknown sediment samples. The natural zeolite appeared to closely simulate the ablation behavior and property of the samples, and it is found to be a potential suitable matrix for the quantitative LIBS analysis of sediments.

Quantitative analysis of metals in waste foundry sands by calibration free-laser induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was applied for quantitative analysis of the elemental composition of waste molding and core sands produced from industry as part of the casting process. To perform the analysis, waste foundry sands (WFS) were collected from metalcasting foundries and prepared in the form of solid pellets with the addition of polyvinyl alcohol as binder. The measurements were carried out using the Mobile double pulse instrument for LIBS analysis (Modì). The spectral analysis was carried out with the calibration-free approach (CF-LIBS). Metal elements commonly found in WFS including Al, Ba, Fe, Li, Mg, Mn, Pb, Ti, Zr, and Zn, were detected and quantified. The metal concentrations for WFS were compared with virgin sand to assess the influence of the casting material as well as the binders used in the foundries to reclaim the sands. The results demonstrated the feasibility of LIBS method as an alternative or complementary technique for the chemical characterization of WFS.

Evaluation of Hexadate Ligand 1, 3-bis(2,2’:6’,2’’-Terpyridyl-5-Ylmethylsulfany l)Propane in the Determination of Iron(II) in Solution by Spectrophotometric and Fluoremetric Methods of Analysis

Uv-visible and fluorescence spectra of the ligand 1,3-bis(2,2’:6’,2’’-ter- pyridyl-5-ymethylsulfanyl)propane L and it’s iron(II) complex have been investigated for analytical purposes. The two spectra of L and terpy are very similar which confirmed the ability of L to co-ordinate through the six N atoms of L with minimum distortion of the metal ion’s octahedral geometry. The ligand-based absorption band of L is shifted to the longer wavelength. It was found that L is able to displace the two terpyridine groups in the complex to give [FeL]2 . The high stability of the complex makes it good in spectrophotometry analysis of metals ions in solution. The fluorescence of L was progressively quenched with an increasing concentration of iron(II). This makes L a possible reagent for the quantitative analysis of metal by measuring fluorescence quenching.

Toxicity and genotoxicity assessment in sediments from the Matanza-Riachuelo river basin (Argentina) under the influence of heavy metals and organic contaminants

The aim of this study was to investigate the parameters of chemical extraction associated with the detection of toxicity and genotoxicity in sediment sample extracts. Quantitative analysis of metals and polycyclic aromatic hydrocarbons (PAHs), together with a battery of four bioassays, was performed in order to evaluate the extraction efficiency of inorganic and organic toxicants. The extracts were carried out using two inorganic solvents, two organic solvents and two extraction methodologies, making a total of five extracts. Two toxicity tests, the algal growth inhibition of Pseudokirchneriella subcapitata and the root elongation inhibition of Lactuca sativa, and two genotoxicity tests, the analysis of revertants of Salmonella typhimurium and the analysis of micronuclei and chromosomal aberrations in Allium cepa, were performed. According to the chemical analysis, the acidic solution extracted more heavy metal concentrations than distilled water, and dichloromethane extracted more but fewer concentrations of PAH compounds than methanol. Shaker extracts with distilled water were non-toxic to P. subcapitata, but were toxic to L. sativa. The acidic extracts were more toxic to P. subcapitata than to L. sativa. The methanolic organic extracts were more toxic to the alga than those obtained with dichloromethane. None of these extracts resulted toxic to L. sativa. Mutagenic effects were only detected in the organic dichloromethane extracts in the presence of metabolic activation. All the inorganic and organic extracts were genotoxic to A. cepa. This study showed that the implementation of different extraction methods together with a battery of bioassays could be suitable tools for detecting toxicity and genotoxicity in sediment samples.

A multi-element screening method to identify metal targets for blood biomonitoring in green sea turtles (Chelonia mydas)

Biomonitoring of blood is commonly used to identify and quantify occupational or environmental exposure to chemical contaminants. Increasingly, this technique has been applied to wildlife contaminant monitoring, including for green turtles, allowing for the non-lethal evaluation of chemical exposure in their nearshore environment. The sources, composition, bioavailability and toxicity of metals in the marine environment are, however, often unknown and influenced by numerous biotic and abiotic factors. These factors can vary considerably across time and space making the selection of the most informative elements for biomonitoring challenging. This study aimed to validate an ICP-MS multi-element screening method for green turtle blood in order to identify and facilitate prioritisation of target metals for subsequent fully quantitative analysis. Multi-element screening provided semiquantitative results for 70 elements, 28 of which were also determined through fully quantitative analysis. Of the 28 comparable elements, 23 of the semiquantitative results had an accuracy between 67% and 112% relative to the fully quantified values. In lieu of any available turtle certified reference materials (CRMs), we evaluated the use of human blood CRMs as a matrix surrogate for quality control, and compared two commonly used sample preparation methods for matrix related effects. The results demonstrate that human blood provides an appropriate matrix for use as a quality control material in the fully quantitative analysis of metals in turtle blood. An example for the application of this screening method is provided by comparing screening results from blood of green turtles foraging in an urban and rural region in Queensland, Australia. Potential targets for future metal biomonitoring in these regions were identified by this approach.

Multispecies acute toxicity evaluation of wastewaters from different treatment stages in a coking wastewater-treatment plant.

Coking wastewater contributes approximately 5% of the total discharge volume of industrial wastewaters every year in China. The toxicity of coking wastewater to aquatic organisms is still unknown. The authors evaluated the toxicity of wastewater from different treatment stages in a coking wastewater treatment plant, South China, using 5 test species belonging to different trophic levels: luminous bacteria, green alga, a crustacean, duckweed, and zebrafish embryos. The raw influent displayed the highest toxicity to the test species, with toxic units ranging from 16.2 to 1176. The toxicity in the wastewater was then gradually removed by sequential primary treatment, biological fluidized-bed treatment, and secondary clarifier treatment. The toxic unit of the final effluent was reduced to 2.26 for the green alga (Pseudokirchneriella subcapitata) and to 0 for the other 4 organisms. Quantitative analysis of metals and polycyclic aromatic hydrocarbons (PAHs) and qualitative scanning by gas chromatography-mass spectrometry showed the presence of a variety of pollutants in the coking wastewaters. Multivariate statistical analysis revealed that the toxicity in the coking wastewater was correlated to the chemical oxygen demand, total nitrogen, ammonia nitrogen, volatile phenols, sulfide, metals (Cr, As, Sb, Hg, Pb, and Ni), and ΣPAHs. Based on the results, it is required to set a safety emission limit value for the discharge of coking wastewater to protect aquatic organisms in the receiving water bodies.

2D Quantitative Analysis of Metal Foaming Kinetics by Hot‐Stage Microscopy

Hot-stage microscopy commonly used in materials science, coupled with image analysis software (ImageJ) is proposed for the first time as an alternative and simple approach for visualizing the metal foam evolution and the thermal events occurring onto the external surface skin, as well as to obtain the expansion curve of foamable precursor material prepared by powder metallurgical method.

APPLICATION OF FRACTOGRAPHY IN ASSESSMENT OF COMPOSITE LAYERS

We used fractography to evaluate morphology of fractures across mono- and multi-component system coatings deposited by PVD technology to the steel substrate. Nanoindentation measurements with dynamic loading were carried out on deposited layers of TiN and AlTiCrN type in order to verify their deformation behaviour. The qualitative and quantitative analysis of metal and non-metal elements across the deposited layers was carried out by GDOES (Glow Discharge Optical Emission Spectroscopy) technique. On the basis of obtaining the results we evaluated structural, mechanical and chemical properties of the deposited types of coatings and recommended their use in practice .

Determination of metal ions in single wood fiber by LA-ICP-MS

Abstract Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to determine the distribution of metal elements in single wood fiber of kraft pulp. Calibration procedures for quantitative analysis of metals in single fibers (SFs) by LA-ICP-MS technique were also developed. Calibration curves were constructed by using matrix-matched standards prepared from (a) cellulose powder washed with 0.05 M EDTA, (b) unbleached softwood pulp washed with 0.05 M EDTA and nitric acid. Calibration materials were prepared by doping the washed cellulose powder and the washed unbleached softwood pulp with standard solutions with increasing concentrations of the elements of interest (Co, Mg, Cu, Na, K, Mn, Zn, Ni, Ca, and Fe). Quantitative determination of the metals in single wood fiber was based on the calibration curves resulting from both the doped cellulose pellets and the doped SFs. The determination of the absolute concentration of elements in a single wood fiber by LA-ICP-MS is still difficult, but in this study, it was demonstrated that the information about the metal distribution can be obtained easily, and their semiquantitative determination is possible.

Johan Klaas Terlouw, Scientist

It gives me great pleasure to introduce this special issue of the European Journal of Mass Spectrometry, created to celebrate the achievements of Hans Terlouw. It will necessarily be a somewhat personal account, because of my long-standing friendship and productive collaboration with JKT over nearly 40 years of research into the mysteries of gas phase ion chemistry. We have shared countless, intense hours of experimental mass spectrometry that produced a very satisfying number of mini-Eureka moments. We were also extremely fortunate to be able to spend many long discussions (in person and by trans-Atlantic ‘phone call) with the late Fred Lossing whose scientific wisdom, good humour and great technical expertise with his electron monochromator, provided the quantitative energetic foundations for so many of our mass spectral observations. Hans was born in Gouda in 1945 and his University education was completed at the University of Utrecht. After his BSc degree in 1965, which inter alia produced his first publication, he obtained an MSc in 1968, working in analytical chemistry. His PhD research was directed by Professor Geo Dijkstra, culminating in his PhD in 1972 and followed by his appointment as Assistant Professor. The thesis was entitled “A new approach to the quantitative analysis of metals by electron impact ionization mass spectrometry.” Of his first nine publications (up to 1974), five concerned the trace analysis of metals by MS. His first independent research was on the pyrolysis of cannabidol and related metastable ion and isotopic labelling studies of isomeric cannabinoids. At the 1973 International MS meeting at Edinburgh University, Professor Dijkstra asked me if I would accommodate Hans in my Ottawa laboratory for a year’s visiting Fellowship. Hans came to see me shortly thereafter at University College (London) where I was on sabbatical leave and the rest, as they say, is our history. It is difficult to overstate the value of a close, non-competitive collaboration in science and the following 15 or so years were exceptionally happy and productive, each of us spending extended visits in the other’s laboratory and inter alia getting to know each others’ co-workers. I find that we have co-authored some 70 articles in books, reviews and journals. Our first joint venture in 1973/4 involved metastable ions studies, using an AEI MS902S mass spectrometer. We then believed that analysis of metastable peak shapes could provide a useful method for ion structure identification. Fortuitously we began with the C2H4O +• isomers, vinyl alcohol, acetaldehyde and oxirane, each of which is readily identified by the characteristic profiles of their metastable H• loss peaks. Johan Klaas Terlouw, Scientist

Effects of different drying processes on the concentrations of metals and metalloids in plant materials

The drying process of fresh plant materials may affect the porous structure, dehydration and a number of quality characteristics of these materials. Therefore, this study has investigated the effect of different drying processes on the variation of metal and metalloid concentrations in the dried plant materials. Seven varieties of native plant species collected from Sao Domingos mine were analyzed by instrumental neutron activation analysis (INAA) to investigate the effects of freeze-drying (FD), ambient air-drying (AAD) and oven-drying (OD) process on the concentrations of metals and metalloids in the plant biomass. Comparison of ambient air-dried, oven-dried and freeze-dried preparations allows a phenomenological description of the dehydration artefacts. In the quantitative analysis of metals and metalloids, FD and OD plant samples show the higher concentrations of metals and metalloids when compared to those in the AAD plant biomass. The freeze-drying process is comparatively reliable for determination of metals and metalloids concentrations in plant materials.

Substrate-assisted laser desorption inductively-coupled plasma mass spectrometry for determination of copper in myeloid leukemia cells

This work presents a detailed characterization of substrate-assisted laser desorption inductively coupled plasma mass spectrometry (SALD ICP-MS), a new approach in the determination of trace elements in submicrolitre volumes. SALD ICP-MS allows quantitative analysis of metals in liquid samples with defined volumes deposited onto an absorbing substrate due to complete sample desorption at relatively low laser power density. Analysis of model samples of Cu(II) showed a constant signal over a wide range of laser power density, an independence of signal on desorption modes and a wide linear dynamic range. SALD ICP-MS with its limit of detection for copper below 26 fg in submicrolitre samples was successfully applied to investigate cytotoxic effects of disulfiram in human myeloid leukemia cells U937 depending on intracellular levels of copper.

Peat as a natural solid-phase for copper preconcentration and determination in a multicommuted flow system coupled to flame atomic absorption spectrometry

The physical and chemical characteristics of peat were assessed through measurement of pH, percentage of organic matter, cationic exchange capacity (CEC), elemental analysis, infrared spectroscopy and quantitative analysis of metals by ICP OES. Despite the material showed to be very acid in view of the percentage of organic matter, its CEC was significant, showing potential for retention of metal ions. This characteristic was exploited by coupling a peat mini-column to a flow system based on the multicommutation approach for the in-line copper concentration prior to flame atomic absorption spectrometric determination. Cu(II) ions were adsorbed at pH 4.5 and eluted with 0.50 mol L −1 HNO 3. The influence of chemical and hydrodynamic parameters, such as sample pH, buffer concentration, eluent type and concentration, sample flow-rate and preconcentration time were investigated. Under the optimized conditions, a linear response was observed between 16 and 100 μg L −1, with a detection limit estimated as 3 μg L −1 at the 99.7% confidence level and an enrichment factor of 16. The relative standard deviation was estimated as 3.3% ( n = 20). The mini-column was used for at least 100 sampling cycles without significant variation in the analytical response. Recoveries from copper spiked to lake water or groundwater as well as concentrates used in hemodialysis were in the 97.3–111% range. The results obtained for copper determination in these samples agreed with those achieved by graphite furnace atomic absorption spectrometry (GFAAS) at the 95% confidence level.

Quantitative analysis of metals in soil using X-ray fluorescence

Using energy dispersive X-ray fluorescence analysis with an X-ray tube filtered with Ti, it was possible to determine the concentration at ppm level of several elements (K, Ca, Ti, Mn, Fe, Cu, Zn, Ga, Br, Rb, Sr, Zr, Y and Pb) in soil treated with organic compounds of urban garbage. It was possible to observe a significant increase in the contents of K, Ca, Zn, Rb, Sr, Zr and Pb in the soil treated in comparison with the soil control.