Inductively Coupled Plasma Optical Emission Spectrometry Research Articles

Evaluation of heavy metals contamination in Rabbit Fish (Signus Sutor) from selected landing sites in Zanzibar, Tanzania

The increase of heavy metals concentrations in aquatic and terrestrial environments and their toxicity is of global concern. The bioaccumulation of toxic metals in fish poses a serious risk to human health when consumed. This study assessed the quality of Rabbit fish (Signus Sutor) and their associated health risks from four landing sites (namely Malindi, Mazizini, Kizimkazi and Matemwe) in Zanzibar. The concentrations of toxic metals, including Lead (Pb), Cadmium (Cd), Copper (Cu), Chromium (Cr), Nickel (Ni), and Arsenic (As), in the fish muscle were scrutinized using inductively coupled plasma optical emission spectrometry (ICP-OES). The detected mean concentration (mg/kg) of Pb, As, Cr, Cd, Cu, and Ni at Malindi were 0.25±0.14, 2.22±0.44, 0.02±0.02, 0.01±0.00, 0.02±0.02 and 0.00±0.00 respectively; at Kizimkazi were 0.39±0.39, 2.30±0.44, 0.11±0.01, 0.07±0.04, 0.17±0.13 and 0.15±0.04 respectively: at Matemwe were 0.38±0.12, 0.52±0.14, 0.04±0.02, 0.05±0.01, 0.65±0.21 and 0.09±0.03 respectively; and Mazizini were 0.21±0.12, 5.56±1.37, 0.02±0.02, 0.03±0.01, 0.05±0.02 and 0.15±0.05 respectively. The mean concentration levels detected for all the elements in the fish gathered from all four landing sites were below international and local maximum (FAO/WHO) permissible limits for human consumption, except for Arsenic (As) and lead (Pb). The study also investigated the relationship between fish size and metal concentration which shows a positive correlation for Cu and Ni. However, it was negative for the remaining metals, possibly due to ecological and metabolic differences. The study emphasizes the necessity for regular monitoring of the marine environment and enforcement of hygienic regulations, as well as the treatment of land-based pollutants before they are discharged into the marine environment to protect fish quality.

Determination of Phytochemical Composition in Fruits and Leaves from Different Origins: Black Mulberry, Chokeberry and Elderberry Genotypes

Black mulberry, chokeberry and elderberry have medicinal properties associated with the presence of phytochemicals which are compounds with potential antioxidant properties. The previously published reports have shown that these compounds significantly affect the course of disease processes by counteracting oxidative stress. In this study, the primary anthocyanins were identified using high-performance liquid chromatography – tandem mass spectrometry (LC-MS/MS). Individual phenolic compounds, tocopherols and amygdalin were quantified by high-performance liquid chromatography with diode-array detection (HPLC-DAD). Elemental contents were determined by inductively coupled plasma – optical emission spectroscopy (ICP-OES). The obtained results reveal the significant presence of primary and secondary compounds in the assessed fruits and leaves, with notable variations depending on fruit species and genotypes. The most abundant compounds were phenolic acids and flavonoids. Analyses indicated that chlorogenic acid, rutin, and cyanidin derivatives were predominant phenolic compounds in all fruit species, while phenolic acids and flavonoids were prominent in leaf samples. The highest chlorogenic acid was determined in black mulberry leaves (ranging from 2403.23 to 3542.53 mg/100 g). Generally, the concentration of phenolic compounds were higher in the leaves than in the fruits of the plant. The highest concentration of amygdalin was detected in black mulberry fruits, ranging from 102.12 to 272.46 mg/100 g. Calcium and potassium were the dominant elements in both berries and leaves.

Polycaprolactone/polyacrylic acid/graphene oxide composite nanofibers as a highly efficient sorbent to remove lead toxic metal from drinking water and apple juice

Due to the characteristics of electrospun nanofibers (NFs), they are considered a suitable substrate for the adsorption and removal of heavy metals. Electrospun nanofibers are prepared based on optimized polycaprolactone (PCL, 12 wt%) and polyacrylic acid (PAA, 1 wt%) polymers loaded with graphene oxide nanoparticles (GO NPs, 1 wt%). The morphological, molecular interactions, crystallinity, thermal, hydrophobicity, and biocompatibility properties of NFs are characterized by spectroscopy (scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Thermogravimetric analysis), contact angle, and MTT tests. Finally, the adsorption efficacy of NFs to remove lead (Pb2+) from water and apple juice samples was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). The average diameter for PCL, PCL/PAA, and PCL/PAA/GO NFs was 137, 500, and 216 nm, respectively. Additionally, the contact angle for PCL, PCL/PAA, and PCL/PAA/GO NFs was obtained at 74.32º, 91.98º, and 94.59º, respectively. The cytotoxicity test has shown non-toxicity for fabricated NFs against the HUVEC endothelial cell line by more than 80% survival during 72 h. Under optimum conditions including pH (= 6), temperature (25 °C), Pb concentration (25 to 50 mg/L), and time (15 to 30 min), the adsorption efficiency was generally between 80 and 97%. The adsorption isotherm model of PCL/PAA/GO NFs in the adsorption of lead metal follows the Langmuir model, and the reaction kinetics follow the pseudo-second-order. PCL/PA/GO NFs have shown adsorption of over 80% in four consecutive cycles. The adsorption efficacy of NFs to remove Pb in apple juice has reached 76%. It is appropriate and useful to use these nanofibers as a high-efficiency adsorbent in water and food systems based on an analysis of their adsorption properties and how well they work.

Quantification of Heavy Metal Content in Anadara tuberculosa from the Gulf of Guayaquil Using ICP-OES: Assessing Marine Contamination

The present study was conducted to quantify the heavy metals cadmium, lead, copper, chromium, nickel, and zinc in the bivalve mollusk concha prieta (Anadara tuberculosa) using inductively coupled plasma optical emission spectroscopy (ICP-OES). This research aims to identify whether the bioaccumulated content of heavy metals exceeds the maximum limits established by various public health bodies such as the ONU, FAO, Codex Alimentarius, EEC, and NHI. Samples of the species were collected randomly from three locations in Puerto El Morro, Playas Municipal Market, and La Libertad Seafood Market in the Gulf of Guayaquil. Thirty-three soft tissue samples of Anadara tuberculosa were evaluated, and the values quantified in mg/kg were in the following order: Zn > Cu > Cd > Ni > Cr > Pb.

Effect of tobacco use on cadmium accumulation in the oral keratinized mucosa

BackgroundThis cross-sectional study aimed to evaluate the effect of tobacco use on the accumulation of cadmium (Cd), a carcinogenic element, in the oral keratinized mucosa (OKM).MethodsOKM samples were obtained by standard punch biopsy from nonsmokers (n = 19) and smokers (n = 21). Cd analysis was performed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The calibration curve R2 values for three wavelengths (214,439, 226,502, and 228,802 nm) were at the level of 0.9999. The frequency of consumption of foods that are Cd sources, such as seafood, rice, and vegetables, was assessed in all patients. The age, sex, and nutritional habits of all patients and the frequency of tobacco consumption by smokers were recorded. The independent t-test, Mann–Whitney U test, Fisher’s exact test, and Spearman correlation test were used for the statistical analyses, and p < 0.05 was considered significant.ResultsAlthough the Cd levels in nonsmokers were higher than those in smokers, no statistically significant difference was found (p > 0.05). In smokers, a positive correlation was found between age and Cd level (r = 0.574, p = 0.006). No significant relationship was found between the groups in terms of nutrition or between the frequency of tobacco consumption and Cd accumulation.ConclusionThe OKM may not have the characteristic cumulative accumulation in terms of toxic elements. Changes in the turnover rate, keratinization, and apoptotic mechanisms in the OKM with the thermal/chemical effects of tobacco may be responsible for the difference in Cd accumulation.Trial registration numberTCTR20230206001/06 Feb 2023 (TCTR: Thai Clinical Trials Registry).

Temperature-sensitively dissolving of GGBS in neutral and alkali media

The sensitivity of temperature on the decomposition/polymerisation of ground granulated blast-furnace slag (GGBS) was investigated through the dissolution experiments at high water to solid ratio under controlled temperatures (5, 20, and 40 °C). The aqueous compositions during the dissolution in neutral and alkali media were determined by ICP-OES (Inductively coupled plasma-optical emission spectrometry) and the saturation conditions with respect to the possible precipitations were estimated by thermodynamic modelling. The depolymerisation of silicate groups and the chemically combined water in the residual GGBS was examined by FTIR/SEM (Fourier Transform Infrared spectroscopy/Scanning Electron Microscopy) and TG (Thermogravimetric) analysis respectively. The results demonstrated that the effect of temperature on the dissolution of GGBS is more pronounced from 5 °C to 20 °C than that from 20 °C to 40 °C. The extremely low temperature (∼ 5 °C) restricts the hydration of GGBS even in a high pH environment. The temperature does not affect the depolymerising sequences of silicate groups in GGBS in a neutral environment but changes the overall dissolution rate. The major silicate spices (Q0 to Q3) in GGBS tend to dissolve evenly in DI water, whereas the Q2 tends to depolymerise faster than others in the NaOH solution. The decreasing Ca concentration in the NaOH solution corresponds to the formation of ∼ 50 nm needle-like precipitates regardless of temperature. Based on the results collected, the dissolving potential and the temperature sensitivity of the major components in GGBS can be divided into three batches: the easiest/most sensitive group: Na-Ox; intermediate group: K-Ox, Si-Ox, Ca-Ox, Al-Ox; the hardest/least sensitive group: Mg-Ox. The intermediate batch required an initial activation energy of ∼ 15 kJ/mol in DI water. The relevant data could be considered as experimental evidence in the thermodynamic modelling of the hydration of GGBSs.

Cadmium and lead in fresh vegetables and vegetable products sold on the local market in the Republic of Serbia, 2018–2021

ABSTRACT Cadmium (Cd) and lead (Pb) concentrations were determined in samples of 31 species of vegetables (n = 719) and in vegetable products (n = 17), collected during the period January 2018 to September 2021. These originated from 33 countries, including Serbia. The samples were analysed by inductively coupled plasma – optical emission spectrometry (ICP-OES). Overall, Cd and Pb were found above the limit of detection in 123 (16.7%, n = 736) and 90 (12.2%; n = 736) samples, respectively. According to the former legislation, valid until the end of August 2021, the maximum levels (MLs) of Cd and Pb were exceeded in 1 and 2 samples of vegetables, respectively. Regarding the EU and Serbian legislation which is valid since September 2021 the MLs of Cd and Pb for vegetables were exceeded in 7 samples: Cd in 5 and Pb in 2 samples. In addition, 3 vegetable product samples exceeded the MLs for both cadmium and lead according to both former and current regulations.

Hydrogeochemistry and Water Quality Index for Groundwater Sustainability in the Komadugu-Yobe Basin, Sahel Region

The assessment of hydrochemical characteristics and groundwater quality is crucial for environmental sustainability in developing economies. This study employed hydrogeochemical analysis, geospatial analysis, and groundwater quality index to assess hydrogeochemical processes and quality of groundwater in the Komadugu-Yobe basin. The pH, total dissolved solids (TDS), and electrical conductivity (EC) were assessed in situ using a handheld portable electrical conductivity meter. The concentrations of the major cations (Na+, Ca2+, Mg2+, and K+), were analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The major anions (chloride, fluoride, sulfate, and nitrate) were analyzed via ion chromatography (IC). Total alkalinity and bicarbonate were measured in situ using a HACH digital alkalinity kit by the titrimetric method. Hydrochemical results indicate some physicochemical properties of the groundwater samples exceeded the maximum permissible limits as recommended by the World Health Organization guidelines for drinking water. Gibbs diagrams indicate rock–water interaction/rock weathering processes are the dominant mechanisms influencing the groundwater chemistry. Groundwater is predominantly Ca2+-Mg2+-HCO−3 water type, constituting 59% of the groundwater samples analyzed. The groundwater quality index (GWQI) depicted 63 and 27% of the groundwater samples as excellent and good water types for drinking purposes, respectively. This study further relates the interaction between geology, hydrochemical characteristics, and groundwater quality parameters. The results are essential to inform a sustainable management strategy and protection of groundwater resources.

Ecotoxicological Effects of TiO2 P25 Nanoparticles Aqueous Suspensions on Zebrafish (Danio rerio) Eleutheroembryos.

Among nanoparticles (NPs), titanium dioxide is one of the most highly manufactured worldwide and widely used in multiple products for both industrial use and personal care products. This increases the probability of release into aquatic environments, potentially affecting these ecosystems. The present study aimed to evaluate TiO2 P25 NP toxicity in zebrafish embryos and eleutheroembryos by evaluating LC50, hatching rate, embryo development, and chemical analysis of the TiO2 concentration accumulated in eleutheroembryo tissues. Zebrafish embryos ~2 h post-fertilization (hpf) were exposed to 75, 100, 150, 200, and 250 mg/L TiO2 P25 NPs for 48 and 96 h. A total of 40-60 embryos were placed in each Petri dish for the respective treatments. Three replicates were used for each treatment group. Ti4+ concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), and a conversion factor was used to calculate the TiO2 concentrations in the tissues. The highest calculated concentrations of TiO2 in zebrafish larvae were 1.0199 mg/L after 48 h and 1.2679 mg/L after 96 h of exposure. The toxicological results indicated that these NPs did not have a significant effect on the mortality and hatching of zebrafish embryos but did have an effect on their development. LC20 and LC30 were determined experimentally, and LC50 and LC80 were estimated using four different methods. Up to 11% of embryos also presented physical malformations. These effects can be detrimental to a species and affect ecosystems. Physical malformations were observed in all treatments, indicating teratogenic effects.

Evaluation of Metals in Printed Wiring Boards of Selected Discarded Mobile Phones in Nigeria

Obsolete mobile phones form a major component of the e-waste stream. The Printed wiring boards (PWBs) of mobile phones are packed with economic and toxic metals. Regulatory bodies such as Restriction of Hazardous Substances (RoHS) directives regulate the amount of these toxic metals in electrical and electronic equipment. This study is aimed at evaluating selected critical metals present in PWBs of three popular brands of discarded mobile phones used in Nigeria to understudy the behaviour of original equipment manufacturers (OEMs) regarding toxicity, economic potentials, and level of compliance with international initiatives by regulatory bodies to reduce the level of toxic metals in electronic equipment. PWBs obtained from 60 discarded mobile phones of 3 popular mobile phone brands used in Nigeria were chopped into smaller particles, extracted according to EPA 3050B method, and analysed using the Inductive Coupled Plasma-Optical Emission Spectrometry technique. It was observed that Mn, Fe, Zn, and Cu, had the highest concentration range across all brands studied. Notable toxic metals such as Pb, Cd, Cr, and As have mean and standard deviation values of 0.43±0.38 mg/kg, 0.62±0.160 mg/kg, 5.16±1.06 mg/kg, and 84.97±13.83 mg/kg respectively. Economic metals: Cu, Ag, and Au had mean and standard deviation values of 80.37±16.89 mg/kg, 2.12±0.43 mg/kg, and 0.95±0.19 mg/kg respectively. Results from the study indicate that PWBs of mobile phones are a perfect secondary source of a large variety of metals vital for the recycling industry. Also, the low levels of toxic metals suggest that some OEMs are already adopting the 'design-for-environment' option. Therefore, PWBs studied seem eco-friendly; however, need to be handled with care as there are still some toxic metals of concern not determined in this study.

45S5/PEEK Coatings by Cold Gas Spray with In Vitro Bioactivity, Degradation, and Cellular Proliferation

This study evaluated the biological response of cold-sprayed coatings composed of bioactive glass 45S5 and polyetheretherketone (PEEK). The functional coatings were produced by cold gas spray (CGS) technology, a technique that allows the deposition of powders at significantly low temperatures, avoiding heat damage to polymeric surfaces. By CGS, blends with different ratios of bioactive glass and PEEK powders have been deposited onto PEEK substrates to improve the response of the bio-inert polymer. The bioactivity of the coatings when immersed in a simulated body fluid solution was evaluated by observation with scanning electron microscopy (SEM) and x-ray diffraction (XRD). Results verify that bioactive glass particles in the composite coatings enhance their bioactivity. A degradation test was performed with Tris–HCl solution. From the results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and the weight loss of the samples, it was noticed that the degradation was directly related to the amount of glass in the coatings. Finally, the ability of bone-forming cells to adhere and proliferate on the coatings was evaluated. These experiments showed that the presence of glass particles does not cause a significant increase in cell proliferation. Combining a bioactive material with PEEK leads to forming a final component that provides suitable bioactivity to the final implant.

Adsorption enrichment integrated with paper-based devices for detection of trace levels of hexavalent chromium in water samples.

In the present study, a sensitive microfluidic paper-based analytical device (μ-PADs) integrated with adsorption enrichment procedure was developed to analyze Cr(VI) in water samples. The affecting factors, including pH and amounts of reagents were optimized. The limit of detection of 0.0015mg L-1 and linear range of 0.005-2mg L-1 were achieved with good intra- and inter-day precision of 5.1 and 7.6% RSD, respectively. The results obtained by the proposed method were validated by inductively coupled plasma-optical emission spectrometry (ICP-OES). The recoveries of the present method and ICP-OES were ranged from 96.3 to 109.0‬% and 106.0 to 109.7%, respectively. The two sets of (μ-PADs and ICP-OES) results were in a good agreement as paired t-test indicated no significant differences. The proposed method could be utilized for analyzing trace levels of Cr(VI) in water samples in the absence of conventional analytical instruments.

Imaging of Endometriotic Lesions Using cRGD-MN Probe in a Mouse Model of Endometriosis

Approximately 10% of women suffer from endometriosis during their reproductive years. This disease is a chronic debilitating condition whose etiology for lesion implantation and survival heavily relies on adhesion and angiogenic factors. Currently, there are no clinically approved agents for its detection. In this study, we evaluated cRGD-peptide-conjugated nanoparticles (RGD-Cy5.5-MN) to detect lesions using magnetic resonance imaging (MRI) in a mouse model of endometriosis. We utilized a luciferase-expressing murine suture model of endometriosis. Imaging was performed before and after 24 h following the intravenous injection of RGD-Cy5.5-MN or control nanoparticles (Cy5.5-MN). Next, we performed biodistribution of RGD-Cy5.5-MN and correlative fluorescence microscopy of lesions stained for CD34. Tissue iron content was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Our results demonstrated that targeting endometriotic lesions with RGD-Cy5.5-MN resulted in a significantly higher delta T2* upon its accumulation compared to Cy5.5-MN. ICP-OES showed significantly higher iron content in the lesions of the animals in the experimental group compared to the lesions of the animals in the control group. Histology showed colocalization of Cy5.5 signal from RGD-Cy5.5-MN with CD34 in the lesions pointing to the targeted nature of the probe. This work offers initial proof-of-concept for targeting angiogenesis in endometriosis which can be useful for potential clinical diagnostic and therapeutic approaches for treating this disease.

Ultrafine industrial aerosol as a risk factor for the health of smelting shop workers at a machine-building enterprise

Aim. To evaluate the amount and physicochemical properties of ultrafine industrial aerosol (UIA) in the work zone air (WZA) of smelting shop workers at a machine-building enterprise during various technological processes (melting, welding, and metal machining). Materials and methods. The physical properties of UIA particles were evaluated with NanoScan 3910 scanning spectrometer: the number of particles (number/cm3), particle surface volume (nm3/cm3), particle surface area (nm2/cm2), and nanoparticle mass concentration (μg/cm3) in the WZA of a furnace operator (n = 416), a welder (n = 315), a cutter (n = 286), a grinder (n = 78), and workers of the control group (n = 315). The chemical composition of the air samples was determined by inductively coupled plasma optical emission spectrometry (ICP-OES) using an Optima 2100 DV device. Results. It has been found that the highest concentration of UIA nanoparticles was recorded during metal melting at the workplaces (WP) of furnace operators (4.28 × 104 to 2.41 × 105 particles/cm3) and welders (3.01 × 104 to 3.34 × 105 particles/cm3). During mechanical metal processing, a much smaller number of nanoparticles was produced (for grinders, the number varied from 9.81 × 104 to 1.44 × 105 particles/cm3; for cutters, it varied from 2.71 × 104 to 1.94 × 105 particles/cm3). Indicators of surface area, surface volume and mass concentration at the WPs of furnace operators, welders, grinders and cutters exceeded the corresponding indicators of the control group for almost all sizes of suspended particles with statistically significant differences (p ≤ 0.05). It has been estimated that such metals as Al, Cu, Mg, Mo, Fe, and Ni were present in the workers’ WZA but their content did not exceed the current maximum permissible concentrations. Conclusions. The presence of suspended particles of UIA with a maximum concentration in the range from 20 nm to 70 nm has been confirmed in the WZA during melting, welding of metals and machining. Indicators of concentration, surface area, surface volume, and mass concentration at the workplaces of melting shop workers at the machine-building enterprise significantly exceeded the corresponding indicators in the control group without dust formation processes, showing statistically significant differences (p ≤ 0.05). The evidence of metals in the WZA has suggested their presence in the form of nanoparticles, which are more active and dangerous, thus increasing the risk of their adverse effects on the workers. Ультрадисперсний

Geochemical and petrological studies of high sulfur coal and overburden from Makum coalfield (Northeast India) towards understanding and mitigation of acid mine drainage

Opencast coal mining produces trash of soil and rock containing various minerals, that are usually dumped nearby the abandoned sites which causes severe environmental concern including the production of acid mine drainage (AMD) through oxidation pyrite minerals. The current study entailed assessing the potential production of AMD from an opencast coal mining region in Northeast part of India. In order to have a comprehensive overview of the AMD problem in Makum coalfield, the physico-chemical, geochemical, and petrological characteristics of the coal and overburden (OB) samples collected from the Makum coalfield (Northeast India) were thoroughly investigated. The maceral compositions reveal that coal features all three groups of macerals (liptinite, vitrinite, and inertinite), with a high concentration of liptinite indicating the coal of perhydrous, thereby rendering it more reactive. Pyrite (FeS2) oxidation kinetics were studied by conducting the aqueous leaching experiments of coal and (OB) samples to interpret the chemical weathering under controlled laboratory conditions of various temperature and time periods, and to replicate the actual mine site leaching. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) was operated to detect the disposal of some precarious elements from coal and OB samples to the leachates during our controlled leaching experiment. The Rare earth element (REE) enrichment in the samples shows the anthropogenic incorporation of the REE in the coal and OB. These experiments reveal the change in conductivity, acid producing tendency, total dissolved solid(TDS), total Iron(Fe) and dissolved Sulfate(SO42−) ions on progress of the leaching experiments. Moreover, the discharge of FeS2 via atmospheric oxidation in laboratory condition undergoes a significant growth with the rise of temperature of the reaction systems in the environment and follows pseudo first order kinetics. A bio-remediative strategies is also reported in this paper to mitigate AMD water by employing size-segregated powdered limestone and water hyacinth plant in an indigenously developed site-specific prototype station. Apart from neutralisation of AMD water, this eco-friendly AMD remediation strategy demonstrates a reduction in PHEs concentrations in the treated AMD water.

Ambient Catalytic Spinning of Polyethylene Nanofibers.

A novel single-atom Ni(II) catalyst (Ni-OH) is covalently immobilized onto the nano-channels of mesoporous Santa Barbara Amorphous (SBA)-15 particles and isotropic Anodized Aluminum Oxide (AAO) membrane for confined-space ethylene extrusion polymerization. The presence of surface-tethered Ni complexes (Ni@SBA-15 and Ni@AAO) is confirmed by the inductively coupled plasma-optical emission spectrometry (ICP-OES) and X-ray photoelectron spectroscopy (XPS). In the catalytic spinning process, the produced PE materials exhibit very homogeneous fibrous morphology at nanoscale (diameter: ~50 nm). The synthesized PE nanofibers extrude in a highly oriented manner from the nano-reactors at ambient temperature. Remarkably high Mw (1.62×106 g mol-1 ), melting point (124 °C), and crystallinity (41.8 %) are observed among PE samples thanks to the confined-space polymerization. The chain-walking behavior of surface tethered Ni catalysts is greatly limited by the confinement inside the nano-channels, leading to the formation of very low-branched PE materials (13.6/1000 C). Due to fixed supported catalytic topology and room temperature, the filaments are expected to be free of entanglement. This work signifies an important step towards the realization of a continuous mild catalytic-spinning (CATSPIN) process, where the polymer is directly synthesized into fiber shape at negligible chain branching and elegantly avoiding common limitations like thermal degradation or molecular entanglement.

Heavy metal decontamination by ion exchange polymers for water purification: counterintuitive cation removal by an anion exchange polymer

Ion exchange polymers were used for mercury and lead ions removal in water. The heavy metal ion concentration was analyzed by two independent methods: inductively coupled plasma–optical emission spectroscopy (ICP-OES) and gravimetry. The studied cation exchange polymer (CEP) was sulfonated poly(ether ether ketone) (SPEEK), and the anion exchange polymer (AEP) was poly(sulfone trimethylammonium) chloride (PSU-TMA). The removal capacity was connected with the ion exchange capacity (IEC) equal to 1.6 meq/g for both polymers. The concentration ranges were 0.15–0.006 mM for Hg2+ and 10.8–1.0 mM for Pb2+. SPEEK achieved 100% removal efficiency for mercury and lead if the concentration was below the maximum sorption capacity (Qmax), which was about 210 mg/g for Pb2+ with SPEEK. For PSU-TMA, the surprising removal efficiency of 100% for Hg2+, which seemed incompatible with ion exchange, was related to the formation of very stable complex anions that can be sorbed by an AEP. Langmuir adsorption theory was applied for the thermodynamic description of lead removal by SPEEK. A second-order law was effective to describe the kinetics of the process.

Ambient Catalytic Spinning of Polyethylene Nanofibers

AbstractA novel single‐atom Ni(II) catalyst (Ni‐OH) is covalently immobilized onto the nano‐channels of mesoporous Santa Barbara Amorphous (SBA)‐15 particles and isotropic Anodized Aluminum Oxide (AAO) membrane for confined‐space ethylene extrusion polymerization. The presence of surface‐tethered Ni complexes (Ni@SBA‐15 and Ni@AAO) is confirmed by the inductively coupled plasma‐optical emission spectrometry (ICP‐OES) and X‐ray photoelectron spectroscopy (XPS). In the catalytic spinning process, the produced PE materials exhibit very homogeneous fibrous morphology at nanoscale (diameter: ~50 nm). The synthesized PE nanofibers extrude in a highly oriented manner from the nano‐reactors at ambient temperature. Remarkably high Mw (1.62×106 g mol−1), melting point (124 °C), and crystallinity (41.8 %) are observed among PE samples thanks to the confined‐space polymerization. The chain‐walking behavior of surface tethered Ni catalysts is greatly limited by the confinement inside the nano‐channels, leading to the formation of very low‐branched PE materials (13.6/1000 C). Due to fixed supported catalytic topology and room temperature, the filaments are expected to be free of entanglement. This work signifies an important step towards the realization of a continuous mild catalytic‐spinning (CATSPIN) process, where the polymer is directly synthesized into fiber shape at negligible chain branching and elegantly avoiding common limitations like thermal degradation or molecular entanglement.

Quantification of Bioaccessible and Environmentally Relevant Trace Metals in Structure Ash from a Wildland-Urban Interface Fire.

Wildfires at the wildland-urban interface (WUI) are increasing in frequency and intensity, driven by climate change and anthropogenic ignitions. Few studies have characterized the variability in the metal content in ash generated from burned structures in order to determine the potential risk to human and environmental health. Using inductively coupled plasma optical emission spectroscopy (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS), we analyzed leachable trace metal concentration in soils and ash from structures burned by the Marshall Fire, a WUI fire that destroyed over 1000 structures in Boulder County, Colorado. Acid digestion revealed that ash derived from structures contained 22 times more Cu and 3 times more Pb on average than surrounding soils on a mg/kg basis. Ash liberated 12 times more Ni (mg/kg) and twice as much Cr (mg/kg) as soils in a water leach. By comparing the amount of acid-extractable metals to that released by water and simulated epithelial lung fluid (SELF), we estimated their potential for environmental mobility and human bioaccessibility. The SELF leach showed that Cu and Ni were more bioaccessible (mg of leachable metal/mg of acid-extractable metal) in ash than in soils. These results suggest that structure ash is an important source of trace metals that can negatively impact the health of both humans and the environment.

Synthesis of a Calcium Silicate Cement Containing a Calcinated Strontium Silicate Phase.

The positive effects of strontium on dental and skeletal remineralization have been confirmed in the literature. This study aimed to assess the properties of a calcium silicate cement (CSC) containing a sintered strontium silicate phase. The calcium silicate and strontium silicate phases were synthesized by the sol-gel technique. Strontium silicate powder in 0 (CSC), 10 (CSC/10Sr), 20 (CSC/20Sr), and 30 (CSC/30Sr) weight percentages was mixed with calcium silicate powder. Calcium chloride was used in the liquid phase. X-ray diffraction (XRD) of specimens was conducted before and after hydration. The setting time and compressive strength were assessed at 1 and 7 days after setting. The set discs of the aforementioned groups were immersed in the simulated body fluid (SBF) for 1 and 7 days. The ion release profile was evaluated by inductively coupled plasma-optical emission spectrometry (ICP-OES). Biomineralization on the specimen surface was evaluated by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Data were analyzed by the Kolmogorov-Smirnov test, one-way and mixed ANOVA, Levene's test, and LSD post hoc test (P < 0.05). Except for an increasement in the peak intensity of hydrated specimens, XRD revealed no other difference in the crystalline phases of hydrated and nonhydrated specimens. The compressive strength was not significantly different at 1 and 7 days in any group (P > 0.05). The setting time significantly decreased by an increase in percentage of strontium (P < 0.05). Release of Ca and Si ions significantly decreased by an increase in percentage of strontium (P < 0.05). SEM/EDS showed the formation of calcium phosphate deposits at 1 and 7 days. Incorporation of 10-30 wt% sintered strontium silicate phase as premixed in CSC can significantly decrease the setting time without compromising the compressive strength or biomineralization process of the cement.