Electrothermal Atomic Absorption Spectrometry Research Articles

Rapid and sensitive determination of trace Cd in carbonate samples using direct solid sampling electrothermal vaporization atomic absorption spectrometry

The accurate determination of cadmium (Cd) hosted and accumulated in sedimentary carbonate remains challenging due to its low concentration (ng·g−1) and complex matrix. Conventional methods, such as inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GF-AAS), which typically rely on liquid sampling and sample digestion, are tedious, labor-intensive and time-consuming. In this study, a rapid and sensitive method for the direct determination of carbonate-hosted Cd was developed based on solid sampling electrothermal atomic absorption spectrometry (SS-ETV-AAS). This method eliminates the need of acid digestion procedure, allowing the entire analysis, including sample preparation, to be completed within 10 min. To minimize the carbonate matrix effect, ethylene diamine tetra acetic acid disodium salt (EDTA-2Na) was proposed as matrix modifier to facilitate the release of Cd, enabling fast and accurate determination of trace Cd in carbonate samples. Under optimized conditions, the Cd detection limits was found to be as low as 0.17 ng·g−1, and repeatability (relative standard deviation, RSD) was better than 8 % (n = 7). The accuracy of the proposed SS-ETV-AAS was verified by analyzing five carbonate certified reference materials (GBW07127, GBW07129, GBW07130, GBW07135 and JDo-1), two soil certified reference materials (GBW07404a, GBW07405), as well as several actual carbonate samples. All these results demonstrate that the proposed SS-ETV-AAS method provides a simple, rapid and sensitive approach for measuring trace Cd in carbonates.

Green preconcentration procedures for the determination of aluminium in bottled beverages prior to electrothermal atomic absorption spectroscopy: a comparative study with environmental assessment tools

Green preconcentration procedures for the determination of aluminium in bottled beverages prior to electrothermal atomic absorption spectroscopy: a comparative study with environmental assessment tools

ISFME extraction of As species from some real water samples using an imidazolium-based task-specific ionic liquid (TSIL): Synthesis and characterization

ABSTRACT To determine of arsenic species in real water samples using electrothermal atomic absorption spectrometry, a high-performance in-situ solvent formation microextraction technique has been developed using homogenous liquid – liquid microextraction concepts. The developed method was based on the use of a synthesized imidazolium-based ionic liquid (IL) modified with ammonium pyrrolidine dithiocarbamate as a task-specific ionic liquid (TSIL), which was chelated with As(III) and then converted to a hydrophobic IL using ammonium hexafluorophosphate in anion exchange reactions. As(V) was reduced to As(III), using a satisfied reducing agent, and the total amount of As was analyzed using ETAAS. TSIL acts simultaneously as an extracting solvent and a chelating agent. The characterization of the synthesized TSIL was performed using13CNMR and FTIR analyses. When optimal conditions were met, linear dynamic ranges of 0.5–50 µg/L and 0.5–20 µg/L were obtained in the determination of As(III) and total As, respectively. The limits of detection (LOD) and quantitation (LOQ) were determined to be 0.021 µg/Land 0.064 µg/L for the determination of As(III) (for concentration 20 µg/L), respectively, and the standard deviation (RSD%, n = 7) was 2.0%. To evaluate the validity of the method, it was successfully applied for As species determination in different real water samples.

Recent overview of microextraction of metal ions and pharmaceuticals by solidified floating organic drop microextraction techniques

AbstractThis work presents a comprehensive overview of solidified floating organic drop microextraction, with a particular emphasis on its applications in the analysis of heavy metal ions and different pharmaceutical compounds by sample pretreatment, complexation, and their identification by various analytical techniques. Here, we discussed basic principles, procedures, applications of the technique, and effects of different variables like pH, temperature, stirring rate, extraction time, salts addition, extraction solvent and extraction volume, centrifugation speed, and, vortex time on preconcentration. In brief, the review summarises the various modes of solidified floating organic drop microextraction such as dispersive liquid‐liquid microextraction, ultrasound‐assisted, air‐assisted liquid‐liquid microextraction, and vortex‐assisted solidified floating organic drop microextraction. this review covers the methods combined with analytical techniques such as inductively coupled plasma‐optical emission spectrometry, electrothermal atomic absorption spectrometry, flame atomic absorption spectroscopy, graphite furnace atomic absorption spectrometry, electrothermal vaporization inductively coupled plasma mass spectrometry, high‐performance liquid chromatography, and gas chromatography/mass spectrometry. among these, the incorporation of ultrasonic, vortex, and air agitation improves the dispersion mechanism. The coupling of solidified floating organic drop microextraction with other techniques enhances the selectivity and efficiency of the preconcentration procedure. This review provides a potential overview of the fundamental principles, advancements in various modes, influencing factors, and applications of solidified floating organic drop microextraction, showing its potential for advancements in sample preparation and analytical methodologies across various domains.

Determination of Cr and Ni in Seawater by High-Resolution Continuum Source Electrothermal Atomic Absorption Spectrometry

Determination of Cr and Ni in Seawater by High-Resolution Continuum Source Electrothermal Atomic Absorption Spectrometry

Are lead, cadmium and mercury risk factors for resistant hypertension?

BackgroundLead (Pb), cadmium (Cd) and mercury (Hg) are toxic trace elements that represent a public health problem as risk factors for cardiovascular disease and hypertension (HT) and could also contribute to the development of resistant hypertension (rHT) AimsTo compare the blood concentrations of Pb, Cd and Hg in subjects with resistant and non-resistant HT and to define whether there is a relationship between its levels and rHT. MethodsCross-sectional study. Subjects aged ≥ 21 to ≤ 80 years with a body mass index < 40 kg/m2 were recruited on a discretionary basis from October 2001 to October 2004 in a hypertension unit of a tertiary hospital amongst those sent to the hypertension unit by their family physician. Resistant hypertension was defined according to the American Heart Association (AHA) criteria. Whole blood concentrations of Cd, Pb and Hg were measured by electrothermal atomic absorption spectrometry. Results46 out of 73 included subjects (63%) suffered from rHT. Blood Pb median: HT 3.9 (IQR 2.7–5.2) vs. rHT 3.6 (IQR 2.8–6.0) µg/dL (p=0.941). Blood Cd median: HT 0.07 (IQR 0.07–0.80) vs. rHT 0.30 (IQR 0.07–0.65) µg/L (p=0.681). Blood Hg median: HT 7.9 (IQR 5.8–12.9) vs. rHT 7.3 (IQR 4.6–13.3) µg/L (p=0.611). Considering the 75th percentile of each element (Pb: 5.55 µg/dL, Cd: 0.75 µg/L, Hg: 13.15 µg/L), a multiple logistic regression analysis (adjusted for age, BMI, diabetes mellitus, clearance of creatinine and only for Cd the smoking habit) showed an OR = 3.44 (0.84–14.10, p=0.086) for Pb, OR = 1.80 (0.39–8.24, p=0.451), for Cd and OR = 2.31 (0.59–9.14, p=0.232) for Hg. Moreover, the stratified analyses showed that men with Pb ≥5.55 µg/dL have a 14 times higher risk of suffering from rHT (p=0.026). Interestingly, a 9-fold increased risk was found for non-obese subjects with elevated Pb levels, above 5.55 µg/dL (p=0.029). Also in men, the probability of suffering from rHT was more than 7 times higher if Cd levels were ≥ 0.75 µg/L (p=0.076). Most smokers had higher Cd levels, with a high risk of suffering from rHT (ORa 12.6 (0.8–200.2), p=0.072). ConclusionA higher blood Pb levels, defined by the 75th percentile (Pb ≥ 5.55 µg/dL), is associated with a greater risk of suffering from rHT and to a lesser extent in the case of Cd and Hg.

Effect of Aluminum Concentration in Water on Its Toxicity and Bioaccumulation in Zooplankton (Chaoborus and Chironomus) and Carp (Cyprinus carpio L.) Roe.

An attempt to evaluate aluminum toxicity to living organisms was undertaken in the study. A laboratory experiment was conducted to determine aluminum bioaccumulation and toxicity in Chironomus and Chaoborus larvae and in Cyprinus carpio L. roe depending on aluminum concentration in water reflecting natural chemical composition. Water was examined for temperature, pH, electrical conductivity, dissolved oxygen, color, nitrate nitrogen, nitrite nitrogen, sulfates by spectrophotometric method; total hardness and chlorides by titration method; and calcium, magnesium, sodium by flame atomic absorption spectrometry, total aluminum by electrothermal atomic absorption spectrometry. Determination of aluminum levels in water, roe, and zooplankton was carried out after mineralization using electrothermal atomic absorption spectrometry. Aluminum bioaccumulation factor in roe was determined with respect to concentration in water. Moreover, acute toxicity (LC50) was calculated. In the roe experiment, aluminum concentration in water at the end of the experiment was 0.0635-0.1283 mgAl∙dm-3. The lowest values were noted for the control sample and the highest for water with 0.03 mgAl∙dm-3 aluminum content. The final aluminum level in roe was, like in water, the highest in roe treated with 0.03 mgAl∙dm-3 (18.95 mgAl∙kg-1), and the lowest in roe treated with 3.00 mgAl∙dm-3 (6.96 mgAl∙kg-1). Aluminum bioaccumulation in roe was the strongest in the control. Survival rate ranged from 2.00 to 97.00%, which shows higher sensitivity of roe to aluminum concentration. LC50 value for Chaoborus was 0.6464 mgAl⋅dm-3, and for Chironomus 0.2076 mgAl⋅dm-3 indicating that Chironomus is more sensitive to aluminum toxic effects. Concentration of 3.0 mgAl∙dm-3 caused the highest mortality. Aluminum in both species at each concentration reached the highest levels after one day (24h), 254.58mg⋅kg-1 for Chaoborus and 3107mg⋅kg-1 for Chironomus. After another day, aluminum levels decreased. This demonstrated the differential accumulation of aluminum depending on the species, which predisposes Chironomus as a better indicator organism. This type of research is important from the point of view of aquaculture, which is a targeted activity with a high degree of economic importance, but is also important for aquatic organisms living in natural conditions. Fish reproduction takes place in both types of waters, so all these reservoirs regardless of their source of destination should be inspected.

Fast and simple method for simultaneous determination of palladium and rhodium in spent automotive catalysts by high-resolution continuum source electrothermal atomic absorption spectroscopy

This work established a novel and fast method for the simultaneous determination of palladium and rhodium in spent automotive catalysts by high-resolution continuum source electrothermal atomic absorption spectroscopy (HR-CS ETAAS). For this purpose, a simple approach for the extraction of Pd and Rh from auto catalysts with aqua regia (HCl + HNO3 (3:1)) leaching was developed. The optimum conditions for leaching of both elements in an open system are 4 h, at 108 °C and a solid-to-liquid ratio of 1:40. Palladium and rhodium concentrations in obtained leachate were determined simultaneously in one firing using the less sensitive adjacent secondary lines for Pd at 360.955 nm (7.7% relative sensitivity) and for Rh at 361.251 nm (2.2% relative sensitivity). The pyrolysis and atomization temperatures were 1200 °C and 2600 °C, respectively. Under these conditions, the limits of detection for Pd (0.19 mg kg−1) and Rh (0.48 mg kg−1) were relatively high but the sensitivity of the developed method corresponds to common concentrations of the elements in spent automotive catalysts. The repeatability of the method expressed as a relative standard deviation was typically 10% for Pd and 7% for Rh.The trueness of the method was confirmed by analysis of the certified reference material – spent automobile catalyst (ERM EB 504). The recoveries of Pd and Rh from the spent automobile catalyst were 96.9%, and 87.9%, respectively. The method was successfully applied to the simultaneous determination of Pd and Rh in spent automotive catalysts without preliminary chemical separation.

Green direct ultrasonic slurry sampling and electrothermal atomic absorption spectrometry method for metal analysis of solid plastics samples.

This work presents a "green" analytical method developed for the determination of potentially toxic metals such as aluminium, barium and chromium in solid plastics samples using the slurry sampling technique in conjunction with electrothermal atomic absorption spectrometry. The development of the slurry sampling technique in conjunction with electrothermal atomic absorption spectrometry entailed optimisation of the measuring conditions, which included optimisation of the temperature programme, selection of an appropriate liquid medium for slurry preparation, optimisation of the concentration and volume of the liquid medium and optimisation of the mass of the solid plastics sample. The following conditions were determined: the optimal pyrolysis temperature for aluminium, barium and chromium was in the range of 1300 °C to 1700 °C and the optimal atomisation temperature was in the range of 2100 °C to 2400 °C. The optimal liquid media for solid plastics samples were H2O, 0.2% (v/v) HNO3 and 0.2% (v/v) HCl. The optimal volume of liquid medium was in the range from 5 to 15 mL and the mass of the solid plastics samples was in the range from 30 to 100 mg. The limit of detection and limit of quantification were estimated as 0.06-0.52 ng g-1 and 0.22-1.69 ng g-1 for aluminium, 0.11-0.94 ng g-1 and 0.37-3.14 ng g-1 for barium and 0.07-0.31 ng g-1 and 0.25-1.04 ng g-1 for chromium. Relative standard deviation was below 5% for all plastic samples analysed. Based on the established validation parameters, the slurry sampling technique in conjunction with electrothermal atomic absorption spectrometry represents a viable technique for metal analysis of a variety of plastic materials. The concentrations of analytes in individual solid plastic samples were in the range of 1.36 ± 0.06 μg g-1 to 22.65 ± 0.66 μg g-1 for aluminium, 1.13 ± 0.03 μg g-1 to 6.01 ± 0.22 μg g-1 for barium and 0.60 ± 0.03 μg g-1 to 10.48 ± 0.46 μg g-1 for chromium.

Final report for SIM.QM-S12: supplementary comparison for trace elements in natural water

Main textThe SIM Supplementary Comparison SIM.QM-S12 for Trace Elements in Natural Water was undertaken to assess and demonstrate the analytical capabilities of national metrology institutes (NMIs) and designated institutes (DIs) of SIM members (or other regions) for the accurate determination of trace elements in natural water at µg/kg levels.Evidence of successful participation in formal, relevant international comparisons is needed to document calibration and measurement capability claims (CMCs) made by NMIs and DIs.Seventeen NMIs and DIs participated. Participants were requested to evaluate the mass fractions, expressed in µg/kg, of arsenic, cadmium, lead and antimony in a natural mineral groundwater that was spiked with the respective elements. A variety of instrumental techniques including inductively coupled plasma mass spectrometry (ICP-MS), isotope dilution ICP-MS (ID-ICP-MS), inductively coupled plasma optical emission spectrometry (ICP-OES), electrothermal atomic absorption spectrometry (ETAAS) and hydride generation flame atomic absorption spectrometry (HG-FAAS) were used by the participants for the determination.The NIST decision tree was used to assign the SCRV estimate for the proposed measurands and to calculate the degrees of equivalence of each national measurement standard following the IAWG Guidance on Using NIST Decision Tree for Comparison Reporting from 30 June 2023.Successful participation in SIM.QM-S12 demonstrates measurement for determination of elements in water matrices. Considering the IAWG Core Capability Matrix, this material falls into the matrix challenge called "Water/aqueous", which corresponds to the CCQM amount-of-substance category fresh water, and so will support CMCs for the metalloids and semi-metals at mass fraction levels below 50 µg/kg (As and Sb measurements) and transition elements at mass fraction levels below 50 µg/kg (except Hg) (for Cd and Pb measurements).To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Holistic food safety evaluation of herbs: methods for the determination of organic and inorganic trace contaminants in Moringa stenopetala as a case study.

Moringa stenopetala is considered a superfood due to the many bioactive compounds that it provides to the diet. However, like all edible plants, it is mandatory to guarantee food safety. Thus it is necessary to develop analytical methods that can rapidly and accurately determine hazardous pollutants, to evaluate compliance with food regulations. In this regard, two multi-component procedures were developed trying to cover some of the main organic and inorganic potential contaminants. A microwave-assisted digestion followed by electrothermal atomic absorption spectrometry was used for arsenic, cadmium, and lead determination, while a modification of the QuEChERS protocol followed by gas chromatography-tandem mass spectrometry was employed for the determination of 55 pesticides from different families. Both analytical methods were thoroughly validated according to international guidelines. The analyzed samples obtained from the Uruguayan market showed compliance with both, national and international, food regulations. The holistic approach employed in this research is not commonly presented in the literature, thus constituting a novel way to face food safety.

Gold Determination by Electrothermal Atomic Absorption Spectrometry After Preconcentration Using Natural Deep Eutectic Solvent Based on Menthol and Camphor

Gold Determination by Electrothermal Atomic Absorption Spectrometry After Preconcentration Using Natural Deep Eutectic Solvent Based on Menthol and Camphor

Determination of Polyorganosiloxanes (by Silicon) in Water by Extraction High-Resolution Continuum Source Electrothermal Atomic Absorption Spectrometry

Determination of Polyorganosiloxanes (by Silicon) in Water by Extraction High-Resolution Continuum Source Electrothermal Atomic Absorption Spectrometry

Determination of Ag in high-purity solutions of copper and nickel by high-resolution continuum-source electrothermal atomic absorption spectrometry (HR-CS-ETAAS)

A need to control the silver content in high-purity copper and nickel samples is attributed to the deterioration of the technical characteristics of materials when the presence of such impurities exceeds the permissible levels. In this study, modes for the determination of Ag in copper and nickel by high-resolution electrothermal atomic absorption spectrometry with a continuum source at a content of 10–6 – 10–5 % have been developed. The optimal temperature regimes of the atomizer program and the amount of chemical modifier introduced were developed proceeding from the results of studying the regularities of atomic absorption measurements of silver in matrix solutions of Cu and Ni (with a concentration of 10 g/liter each). To construct calibration dependences, aqueous standard solutions of the analyte (determination in copper) and aqueous standard solutions of the analyte with the addition of nickel nitrate 10 mg/liter (determination in nickel) were used. The atomization temperature was chosen to be 1600°C. The dosing volume of the solutions in the graphite furnace was always 20 μl. When determining Ag in high-purity copper, different temperatures of the pyrolysis stage were used for measurements with dosing of standard analyte solutions (600°C) and for measurements with dosing of the analyzed copper solution (800°C). In the determination of silver in nickel solutions, the temperature of the pyrolysis stage was 800°C. The developed conditions for the determination of silver were tested in the analysis of high-purity samples of copper and nickel (standard solutions of Inorganic Ventures, USA with a concentration of 10 g/liter) using spiked tests. The maximum value of the relative error of determinations does not exceed 13%. The detection limits for silver were: 1.8 × 10–6 % in copper and 3.2 × 10–6 % in nickel.

Aerosol Inhalation Delivery of Ag Nanoparticles in Mice: Pharmacokinetics and Antibacterial Action.

The aerosol inhalation delivery of composite particles consisting of Ag nanoparticles enveloped by polyvinylpyrrolidone was investigated in experiments with mice. An ultrasonic nebulizing system was created for the generation of aerosols with a mean diameter and mass concentration of 700 ± 50 nm and 65 ± 5 mg/m3, respectively. The mass fraction of Ag in the composite particles was α = 0.061. The aerosol delivery was performed in a whole-body chamber with an exposition time of 20 min. Pharmacokinetic measurements were taken and the silver concentrations in the blood and lungs of the mice were measured as a function of time after exposition by means of electrothermal (graphite furnace) atomic absorption spectrometry. The inhalation dose and other pharmacokinetic parameters were determined. The antibacterial effect of aerosolized silver was assessed for mice infected with Klebsiella pneumoniae 82 and Staphylococcus aureus ATCC 25953. The survival rate of the infected mice after the aerosol exposure demonstrated the high antibacterial efficiency of Ag nanoparticles after inhalation delivery.

Metallomics as an Essential Analytical Tool for the Development of Potential Metallodrugs

Metallomics is an emerging area of the omics disciplines that has grown enormously since its conception as an academic discipline in 2004. This discipline integrates research related to biometals, along with other disciplines such as genomics, proteomics, metabolomics, and bioinorganic chemistry. It is defined as the study of the metallome, the interactions and functional connections of metal ions or species with genes, proteins, metabolites, and other biomolecules in biological systems. The study of the metallome of a species can provide information on the distribution of an element between cellular compartments, on the coordination environment in which a biomolecule is incorporated, or on the concentration of individual metal species present. In this regard, it plays a very important role in providing integrated information that connects metallomics with other omics disciplines.1,2 The term ‘metallomics’ was pronounced for the first time in June 2002 during the Tokushima Seminar on Chemical Engineering held in Tokushima, Japan, where the development of this new omics discipline was suggested, which was closely influenced by the progress of Analytical Atomic Spectrometry, in particular by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Since the mid-1970s, ICP-MS and ICP-AES techniques have been positioned as highly sensitive analytical tools with excellent possibilities for simultaneous quantification of multiple elements. Nowadays, it is possible to carry out analyses of basically all the elements in any type of sample using one of these two techniques. Likewise, the use of several other techniques for metallomic studies has been reported, such as Electrothermal Atomic Absorption Spectrometry (ETAAS), Microwave Plasma Atomic Emission Spectrometry (MP-AES), Laser Induced Plasma Spectroscopy (LIBS), and Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF), among others.2 A very useful bioanalytical study, within the field of metallomics, is the cellular uptake assay of potential metallodrugs. Using an adequate analytical technique, the metallic center of a given metallodrug can be monitored, and thus the fraction capable of entering a certain type of cell can be evaluated. Likewise, the distribution at the subcellular level and the association of the studied metallodrug with biomacromolecules of interest may be studied. In this context, our research group has been working on the optimization and validation of different bioanalytical methods for monitoring potential metallodrugs with activity against Trypanosoma cruzi, a protozoan parasite that causes Chagas disease, which is a pressing health problem in high-poverty areas of Latin America.3 A large number of metallic compounds with anti-Trypanosoma cruzi activity have been synthesized by our group, using as a strategy the coordination of metal ions or organometallic centers of pharmacological importance with bioactive organic ligands that have proven activity against Trypanosoma cruzi. Binding to metal can modify properties such as the solubility, lipophilicity, stability, and electronic and transport properties of the organic ligand, generating compounds that may be more active and/or less toxic. These metallic compounds can act by affecting two or more targets in the parasite: the ligand itself and others resulting from the presence of the metal. The biological properties of the metal–bioactive ligand compound will depend on the nature of the metallic center and the bioactive ligand, the presence of other ligands, and, fundamentally, its physicochemical-structural properties. In this regard, our group has focused its attention on the rational design of antiparasitic metallic compounds based on the relationships between chemical structure, physicochemical properties, and biological activity. This research line has led to important contributions that have been transferred to the scientific field, showing the vital importance of cellular uptake metallomic studies to understand the fate of potential metallodrugs and elucidate targets and mechanisms of action. In this context, the potential as an antitrypanosomal agent of a new rhenium(I) tricarbonyl compound with the formula fac-[Re(I)(CO)3(tmp)(CTZ)](PF6), where CTZ = clotrimazole and tmp = 3,4,7,8-tetramethyl-1,10-phenanthroline, was recently evaluated. It showed very good activity against the epimastigote form of Trypanosoma cruzi, with IC50 values (half maximal inhibitory concentration) in the low micromolar range. For this task, a new bioanalytical method based on the MP-AES technique was developed and validated.3 This technique has reemerged in the last few years with several improvements and can be considered as a good strategy for the determination of highly refractory elements such as rhenium. The method was applied to the determination of the percentage of rhenium taken up by the parasites and the association of the compound with the main biomacromolecules: soluble proteins, insoluble fraction, DNA, and RNA. The results of the metallomic study showed a low percentage of total rhenium taken up by the parasites, around 1 %, and a preferential accumulation in the soluble protein fraction, around 83 %. Also, the low localization of the compound in the DNA and RNA fractions, less than 1 %, made it possible to discard these biomolecules as the main targets of action. The developed method turned out to be an economical and efficient alternative for metallomic studies of potential rhenium metallodrugs, applied for the first time for the analysis of this particular element.3 In order to deepen in the localization of the compound taken up in the whole parasite, confocal Raman microscopy was performed.4 However, the main bands of the rhenium(I) tricarbonyl compound showed a strong overlap with signals coming from lipids, proteins, and DNA from the parasite, and due to the low concentration assayed, signals associated with ν(CO) could not be detected. Notwithstanding that, the overlap found by confocal Raman spectroscopy gave us a clue to the actual location of the compound inside the parasite, constituting an interesting indirect metallomic tool.4 Similar bulk studies were previously carried out by our research group using the ETAAS technique. For this task, novel bioanalytical methods were developed and validated, which were successfully applied to study the cellular uptake of potential palladium, platinum, and vanadium metallodrugs against Trypanosoma cruzi.5,6 This example of interdisciplinary work highlights the importance of developing and validating bioanalytical methods such as metallomic strategies to carry out cellular uptake studies, in order to assess the fate and possible targets and mechanisms of action of potential metallodrugs. Likewise, they promote the key role of Bioanalytical Chemistry in supporting Medicinal Inorganic Chemistry during the development of new potential metallodrugs, in the search for answers to important Public Health issues.

A hydrophobic deep eutectic solvent-based microextraction for the determination of ultra-trace arsenic in foods by an electrothermal atomization atomic absorption spectrometry

A hydrophobic deep eutectic solvent-based liquid-phase microextraction approach for the determination of ultra-trace arsenic (total) in foods by an electrothermal atomization atomic absorption spectrometry was developed. Various deep eutectic solvents based on tetraoctylammonium bromide and fatty acids (heptanoic, octanoic, nonanoic, decanoic acids) were studied as extraction solvents for preconcentration of arsenic (V) from mineralizates obtained after a microwave digestion of food samples. Phenomenon of ion-pairs formation between dihydroarsenate and precursor of deep eutectic solvent (tetraoctylammonium) and mass-transfer of the ion-pairs into deep eutectic solvent phase was presented for the first time. The proposed approach allowed to preconcentrate analyte into the deep eutectic solvent phase without the use of additional organic solvents (emulsifier agents or dispersive solvent), chelating and reducing agents. It was found, that the deep eutectic solvent based on tetraoctylammonium bromide and heptanoic acid provided more effective preconcentration of analyte from mineralizates (95% extraction recovery, 57-fold enrichment factor). The obtained limit of detection, calculated as a triple signal-to-noise ratio, was 10 ng L−1. The microextraction procedure was applied for the determination of trace arsenic in rice and wheat grains samples.

Adaptive Calibration in Electrothermal Atomic Absorption Spectrometry

A method is developed for determining concentrations in Zeeman electrothermal atomic absorption spectrometry based on the conversion of the transformation function of an atomic absorption spectrometer into a calibration dependence adapted to the matrix of the analyzed sample. The transformation function is expressed as a one-parameter saturation function, which is an integral optical characteristic of the spectrometer, independent of the composition of the analyzed sample. The algorithm of the method includes measurement of the analytical signals of an analyzed sample and a same sample with a known additive of the analyte and calculation of the matrix coefficient and the desired concentration of the analyte in the analyzed sample from these signals. The adaptive calibration method is tested for As, Au, Cd, Cu, Mo, Pd, Pb, Mo, Pd, Pb, Ti, V. The relative systematic error in determining the concentration of an element in the range of measuring the absorbance of atomic vapor does not exceed 10%. The analytical ranges for the elements exceed three orders of magnitude.

Heavy metals in ENDS: a comparison of open versus closed systems purchased from the USA, England, Canada and Australia

IntroductionElectronic nicotine delivery systems (ENDS) are known to contain heavy metals such as lead (Pb), nickel (Ni) and chromium (Cr). The presence of heavy metals in ENDS may be due...

The copper chelator ammonium tetrathiomolybdate inhibits the progression of experimental endometriosis in TNFR1-deficient mice

The TNF-α/TNFR system is involved in endometriosis (EDT), a gynecologic estrogen-dependent disease. Elevated copper concentrations have also been associated with EDT, even in TNFR1-deficient mice where disease worsening occurs. We aimed to evaluate whether treatment with ammonium tetrathiomolybdate (TM, copper chelator) is beneficial in TNFR1-deficient mice presenting with worsened EDT status. Female C57BL/6 mice were divided into three groups: KO Sham, KO EDT, and KO EDT+TM. TM was administered from the 15th postoperative day, and samples were collected one month after inducing pathology. In peritoneal fluid, copper and estradiol levels were determined by electrothermal atomic absorption spectrometry and electrochemiluminescence, respectively. Lesions were processed for the analysis of cell proliferation (PCNA immunohistochemistry), expression of angiogenic markers (RT-qPCR), and oxidative stress (spectrophotometric methods). We found that EDT increased copper and estradiol levels compared to the KO Sham group, while the TM administration restored the levels of both factors. TM also reduced the volume and weight of the lesions and cell proliferation rate. Besides, TM treatment decreased the number of blood vessels and the Vegfa, Fgf2, and Pdgfb expression. Furthermore, superoxide dismutase and catalase activity decreased, and lipid peroxidation increased. TM administration inhibits EDT progression in TNFR1-deficient mice where the pathology is exacerbated.