Inductively Coupled Plasma Optical Emission Research Articles

Occurrence of Lead and Other Toxic Metals Derived from Drinking-Water Systems in Three West African Countries.

Background:Exposure to toxic metals (TMs) such as lead can cause lifelong neurodevelopmental impairment and other adverse outcomes. TMs enter drinking water from human activity, geogenic contamination, and corrosion of water system components. Several studies report TM contamination in piped systems and private wells in high-income countries (HICs). However, few robust studies report on TM contamination in low- and middle-income countries (LMICs).Objectives:We characterized the occurrence and investigated sources of TM contamination in 261 rural water systems in three West African LMICs to inform prevention and management.Methods:Water samples were collected from 261 community water systems (handpumps and public taps) across rural Ghana, Mali, and Niger. Scrapings were collected from accessible components of a subset of these systems using a drill with acid-washed diamond-tipped bits. Samples were analyzed by inductively coupled plasma (ICP) mass spectrometry or ICP optical emission spectroscopy.Results:Of the TMs studied, lead most frequently occurred at levels of concern in sampled water system components and water samples. Lead mass fractions exceeded International Plumbing Code (IPC) recommended limits (0.25% wt/wt) for components in 82% (107/130) of systems tested; brass components proved most problematic, with 72% (26/36) exceeding IPC limits. Presence of a brass component in a water system increased expected lead concentrations in drinking-water samples by 3.8 times. Overall, lead exceeded World Health Organization (WHO) guideline values in 9% (24/261) of drinking-water samples across countries; these results are broadly comparable to results observed in many HICs. Results did not vary significantly by geography or system type.Discussion:Ensuring use of lead-free () components in new water systems and progressively remediating existing systems could reduce drinking-water lead exposures and improve health outcomes for millions. However, reflexive decommissioning of existing systems may deprive users of sufficient water for health or drive them to riskier sources. Because supply chains for many water system components are global, TM monitoring, prevention, and management may be warranted in other LMICs beyond the study area as well. https://doi.org/10.1289/EHP7804

Characterization of the Bioaccessibility of Minerals from Commercial Breakfast Cereals by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES)

Traditional chocolate and whole-meal flour breakfast cereals were analyzed to determine the total concentrations and bioaccessibilities of some elements. For the total concentration, the samples were prepared by microwave digestion. In addition, certified reference materials were used to verify the accuracy of the method, which was 82–106% for the analytes. Great variation in the concentrations was observed, possibly due to the raw materials used to produce the cereals. For the bioaccessibility study, an in vitro digestion method was used, and the accuracy was verified by the addition and recovery method. Cu, Fe, Mn, and Zn had detectable bioaccessibilities from 37% to 47%, 1% to 41%, 8% to 61%, and 4% to 24% of the total concentrations, respectively. Aluminum, Ba, and Mo had concentrations below the limit of quantification. Therefore, breakfast cereals complement a healthy diet, since some essential elements have high bioaccessibilities.

The living cells and elemental synthesis: New insights

The generation of new elements inside living cells, either by nuclear fusion or nuclear fission is questionable. Nuclear fusion theory can interpret the increase of an element or reduction of another one following the dissociation of the atomic nucleus of some elements and recoordination of new integrated nuclei, which surrounded by electrons to neutralize protons of nucleus. To proof our hypothesis, in vitro microcosm investigations were carried out using two microbial stains (Bacillus amyloliquefaciens MN592674B and Escherichia coli), which spiked with seven trace elements (Ti, V, Co, Ni, Se, Mo, and B) in a closed system. Total trace element concentrations were determined using Inductivity Coupled Plasma Optical Emission Spectrometry (ICP-OES) at the end of inoculation experiment. Some trace elements (e.g. Se, V and Ni) showed increments, others (e.g. Ti and B) showed reductions; however, some trace elements such as Ag, B and Cd vanished completely from the microbial media. The addition of V, Co, Ni, Se, Mo, and B to B. amyloliquefaciens culture medium enhanced Bismuth (Bi) biosynthesis. This finding was also supported by Energy Eispersive X-ray Spectroscopy (EDS) data, which showed substantial alterations in metals distribution in the outersphere surfaces as affected by the microbial strain and the spiked elements. In this regard, trace elements transformation differed greatly among bacterial strains. Findings from this investigation provide insights for understanding elemental transformations in the living cells.

Risk assessment and study of trace/heavy metals in three species of fish of commercial interest on the island of El Hierro (Canary Islands, eastern-central Atlantic)

The levels of toxic heavy metals (Al, Cd, Pb), macroelements (Ca, K, Mg, Na) and microelements and trace elements (B, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sr, V, Zn) were determined in 54 muscle samples from three species of fish for human consumption, Balistes capriscus (grey triggerfish), Canthidermis sufflamen (oceanic triggerfish) and Heteropriacanthus fulgens (rock catalufa), using spectrometry of inductively coupled plasma optical emission (ICP-OES). The aims of this study is to determine if the three species are good bioindicators of environmental pollution and to verify whether they are suitable for human consumption. Significant differences were found in the levels of Al, B, Fe, K, Mn, Mo, Na and Zn between the three species studied. The results suggest that the underwater volcano off El Hierro influences the metallic content (Al, K the most characteristic) of H. fulgens. An evaluation of the toxic risk derived from the ingestion of B. capriscus, C. sufflamen and H. fulgens was carried out, analyzing the Admissible Daily Intake (ADI) and the Safety Margin (MoS). For the nutritional study, the Recommended Daily Intake (RDI) index was used. Therefore, once the study has been carried out and under the conditions established in terms of daily / weekly fish consumption, proposed by AESAN, there would not be any type of toxic risk after ingesting B. capriscus, C. sufflamen and H. cruentatus.

Determination of Lanthanides in Coal Fly Ash, Sediment and Monazite Sand by Inductively Coupled Plasma Optical Emission Spectrometry After Separation Using Oxalate form of Ion-Exchange Resin

A method has been developed for the separation of lanthanides, Ce, Nd, Gd, La, Pr, Sm, Dy, Eu, Er, Ho, Yb, Tm, Tb and Lu, using oxalate form of Dowex-1, a reactive ion-exchanger. Lanthanides present in such samples as monazite sand, coal fly ash and sediment were separated from matrix at pH 2.5 in a column containing oxalate form of Dowex-1 resin. The samples have been decomposed in H2SO4 and taken in 0.36 M H2SO4 prior to separation. The lanthanides in the column were eluted with 2 M HNO3. Lanthanides present in the eluent were determined by inductively coupled plasma optical emission spectrometry (ICP−OES) and the recovery of analytes ranged from 92 to 105%. Matrix free solutions were analyzed for lanthanides by ICP−OES. The relative standard deviation was in the range of 4–7% and limits of detection were between 0.015–0.16 mg/kg. The developed procedure was applied to the separation and determination of lanthanides in a standard reference material NIST Coal Fly Ash 1633b, a lake sediment and monazite sand. The results obtained by the present method are in close agreement with certified values in case of certified reference material and microwave digestion method for other samples. Accuracy of other samples is ensured based on standard addition recoveries.

Quantitative analysis of zirconium alloys using borate fusion and wavelength dispersive X‐ray fluorescence spectrometry

The National Institute of Standards and Technology uses borate fusion, wavelength dispersive X‐ray fluorescence (WDXRF) spectrometry and synthetic calibration standards for high performance, quantitative analyses of alloys reacted and partially dissolved for fusion into borate beads. Conversion from metal matrix to low Z glass preserves measurement sensitivity. Synthetic calibration standards closely match fused samples, yielding very low uncertainties in results. This approach was applied to zirconium alloys of ≥90% Zr and 17 elements: Al, Co, Cr, Cu, Fe, Hf, Mn, Mo, Nb, Ni, P, Pb, Sn, Ta, Ti, V, and W. To demonstrate capabilities, it was applied to Standard Reference Material (SRM) 360b Zirconium (Sn‐Fe‐Cr) Alloy, renewal SRM 360c, plus discontinued Zr alloy SRMs: 360, 360a, 1210 through 1215, and 1234 through 1239. Eleven elements exhibit biases ≤5% for these SRMs. Additional validation used comparative test methods of inductively coupled plasma (ICP) mass spectrometry, ICP optical emission spectrometry and prompt gamma‐ray activation analysis. This WDXRF method gives results of high enough quality to certify the valid elements in conjunction with results from one or more independent methods. Several phenomena complicate the approach. Normal Zr dissolution using HNO3 + HF, forms Zr(NO3)4 in solution and concentrates it on drying. Zr(NO3)4 sublimes at low temperatures, causing uncontrolled loss of Zr as the temperature exceeds 100°C. Rapidly heated Zr(NO3)4 may explode. Digestion with HF alone works well. High‐purity ZrO2 and LiF were used for matrix matching of calibration standards, requiring determinations of trace elements in the high‐purity ZrO2.

Heavy Metals Accumulation in Different Cultivated Fish Tissues through Commercial Fish Feeds and Health Risk Estimation in Consumers in Bangladesh

Cultivated fishes are major protein and microelement sources for all sorts of people in Bangladesh due to its availability and affordability. Since heavy metals are persistent in the aquatic environment, these metals can accumulate in the food chain. Cultivated fishes containing heavy metals can cause a carcinogenic and non-carcinogenic risk to human as it biologically accumulates heavy metals from commercial feeds. This study was designed to access the content of heavy metals in the flesh of some cultivated fish species through consuming commercial fish feeds available in Bangladesh and potential health risk calculation for consumers due to intake daily. The concentration (mg/kg, dry weight) range of heavy metals like; Pb (4.56- 7.08), Cd (0.23- 1.28), Cr (4.00-7.08), Cu (11.23- 20.62), As (0.08- 0.34), Hg (0.05- 0.34) in selected commercial fish feeds and Pb (4.35-8.03), Cd (0.87- 1.35), Cr (4.71-8.98), Cu (14.00- 31.80), As (0.17- 0.28), Hg (0.08- 0.41) in fishes were accessed by inductive coupled plasma optical emission spectroscopy (ICP-OES). The recorded concentration value for selected metals in fish tissues and feeds were also compared with the safe limit proposed by World health organization (WHO, 1995), Food and Agricultural Organization (FAO, 1983), European Union (EU, 2001). This study also estimated the carcinogenic and non- carcinogenic risk due to daily consumption of these cultivated fishes for a certain age.

Spectrochemical Analysis of Bottled and Tap Water from Selected Counties of Middle Tennessee, USA

A total of 37 elements were determined in tap and bottled water samples from six counties of Middle Tennessee (USA) by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The overarching goal of the study is to dispel the myth that bottled water is better than tap water or vice versa. Other parameters analyzed were pH, conductivity, and Total Dissolved Solids (TDS). The results were compared with the Maximum Contaminant Limit (MCL) reported by the US Environmental Protection Agency (US-EPA). The concentrations of phosphorus, silicon, fluoride, and chloride conformed to the established values by US-EPA maximum contaminant level corresponding value. The level of Aluminum (Al), Boron (B), Chromium (Cr), Cobalt (Co), Copper (Cu), Iron (Fe), Lithium (Li), Manganese (Mn), Nickel (Ni), Titanium (Ti), Vanadium (V), and Zinc (Zn) conformed to the established values by governmental agencies (USEPA). Heavy metals such as Arsenic (As), Cadmium (Cd), Cobalt (Co), Lead (Pb), Mercury (Hg), and Silver (Ag) were detected in the tap water of the urban (Davidson) and urbanizing (Rutherford and Williamson) counties; suggesting that rural counties had a less heavy metal concentration in their drinking water sources than urban counties (P < 0.05). However, the values were below the Maximum Contaminant Levels (MCLs).

Structural characterization of polymeric chitosan and mineral from Omani shrimp shells

Shrimp shell waste is a burden nowadays globally due to its environmental pollutions. However, shrimp shells contain various ingredients such as chitosan, chitin, minerals, and proteins, which are essential for biomedical, agriculture, and industrial sectors. Chitosan is a polymer, and it is characterized by its biocompatibility, biodegradability, and non-toxicity. This study aimed to isolate a good quality chitosan polymer from the shrimp shells waste and characterize it by using spectroscopic methods. Initially, the collected shrimp shells were dried and ground for chemical treatment, collected from different regions of Oman. The coarse samples were dimerization, deproteinization, deacetylation and discoloration by using 1 M hydrochloric acid, 12.5 M sodium hydroxide, and 12 M hydrogen peroxide solution to give the corresponding products. Finally, the isolated chitin samples were deacetylated by microwaving at high temperature and pressure for 15 min. The yield of chitosan was approximately 53.31%, which 8.46 ± 0.06 gm, 7.02 ± 0.01 gm and 5.31 ± 0.01gm were the average weight yield after the demineralization, deproteinization and deacetylation processes, respectively. The degree of deacetylation of the extracted chitosan from the shrimp shells was very high of about 97.35% as calculated and identified by using Nuclear Magnetic Resonance spectroscopy. The content of calcium and phosphorus minerals of the chitosan was 117.6 ± 0.01 and 119.12 ± 0.09 parts per million (ppm), respectively, which was determined by using Inductive Coupled Plasma-Optical Emission Spectroscopy. The morphological feature of the chitosan and standard was examined using Scanning Electron Microscopy and EDX, and the results showed no big morphological difference between the two samples and the elemental compositions were almost the same. The results showed that the obtained isolated chitosan from shrimp shells was highly deacetylated compared to standard chitosan, and it could be useful for the preparation of commercial, industrial products, and pharmaceutical drugs.

Nutritional and Phytochemical Properties of Pachira aquatica Seed Grown in Nigeria

The present study investigated the nutritional and phytochemical properties of seeds oils and flours from Pachira aquatica seed cultivated in Nigeria. Proximate composition and phytochemical composition were determined by standard methods while mineral content of the seed flours and oil was determined using Thermo Scientific iCAP 6200 Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) and Agilent 7900 Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The oil which was extracted using Soxhlet extraction method had a yield of 44.43%. The proximate composition of the flour gave carbohydrate 18.12%; moisture 9.74%; protein 19.90%; ash 4.11%; fat 44.43; fibre 3.70%; while phytochemicals showed that phenol was 4.90 mg/100 g; Tannins 0.76 mg/100g; flavonoids 0.68 mg/100 g; glycosides 17.54%; saponins 6.03% and alkaloids 10.68%. Macro-element concentrations from the seed oil and seed flour respectively were 63.55 and 10611.74 mg/Kg K; 22.38 and 628.44 mg/Kg Mg; 67.55 and 4007.86 mg/Kg P; 52.65 and 1387.00 mg/Kg Ca; 17.95 and 35.23 mg/Kg Na. Micro-elements were 4.18 mg/Kg and 24.59 mg/Kg Cu; 4.43 mg/Kg and 40.16 mg/Kg Fe; 1.50 and 9.61 mg/Kg Mn; 2.92 mg/Kg and 25.68 mg/Kg Zn; 2.74 mg/Kg and 15.40 mg/Kg Al; 0.82 ( mg/Kg103) and 2.27 ( mg/Kg103) Ni; 1.11 ( mg/Kg103) and 3.30 (mg/Kg103); 3.55 (mg/Kg103) and 17.19 (mg/Kg103) B; 0.20 (mg/Kg103) and 0.40 ( mg/Kg103) Mo; 0.01 (mg/Kg103) and 0.03 (mg/Kg103) Se.&#x0D; Toxic elements recorded 0.17 and 0.85 µg/Kg Cr; 0.18 and 0.23 µg/Kg Co; 0.01 and 0.01 µg/Kg As; 0.01 and 0.02 µg/Kg Cd; and 0.09 and 0.11 µg/Kg Pb for the seed oil and seed flour respectively. The investigation showed that Pachira aquatica seed is safe and nutritious for domestic purposes and industrial applications. The energy value indicates that the seed is a good alternative source of energy and could be taken when energy given food is required as it falls within the recommended energy dietary allowances especially for children. The bioactive properties of Pachira aquatica seed shows that it has medicinal potential worth exploring for pharmacological purposes.

Assessment of toxic and essential metals in fish feed ingredients available in different areas of Bangladesh

Contamination of heavy metals in fish feed ingredients is regarded as a major crisis globally especially in developing countries because it may be the source of toxicity in the food chain. Fish farming in Bangladesh is growing very rapidly and fish available in the markets are mostly coming from fish farms where fish farmers mostly use commercial fish feeds manufacturing with different ingredients. In this study, several types of ingredients based on different origins were collected from several areas and after measuring dry weight these were digested by a mixture of acids. This study is concerned to access the toxic and essential metals in different fish feed ingredients which are frequently used to produce commercial fish feed in Bangladesh. The concentration (mg kg-1 dry weight) range of toxic metals such as; Pb (0.56- 1.73), Cd (0.12-0.97), Cr (0.15-0.88), As (BDL), Hg (BDL), Ni (1.10-2.50) and essential metals such as; Fe (13.57-48.96), Cu (10.11-28.09), Zn (10.60-26.25), Na (12.07-35.00), K (13.06-28.97), Ca (10.00-47.96) in selected fish feed ingredients were recorded by Inductive Coupled Plasma Optical Emission Spectroscopy (ICP-OES, Optima 7000DV) with significant variation (P&amp;lt;0.05). The analyzed toxic and essential metal concentrations in most of the ingredients were within the safe limit proposed by World Health Organization, Food and Agricultural Organization and European Union indicating no health risk.

Analytical Concentrations of Some Elements in Seeds and Crude Extracts from Aesculus hippocastanum, by ICP-OES Technique

The metal content in some samples of horse chestnut seeds (Aesculus hippocastanum) was monitored over time (years 2016–2019) considering the two most common and representative Mediterranean varieties: the pure species (AHP, which gives white flowers) and a hybrid one (AHH, which gives pink flowers). The selected elemental composition of the samples was determined by applying the Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) technique. Several samples obtained from different preliminary treatments of the peeled seeds were examined, such as: (i) floury samples (wild-type) mineralized with the wet method; (ii) the ashes of both AHP and AHH varieties; (iii) the fraction of total inorganic soluble salts (TISS). Furthermore, the hydroalcoholic crude extracts (as a tincture) were obtained according to the official Pharmacopoeia methods, and the relevant results were compared with those of a commercial sample, an herbal product-food supplement of similar characteristics. The main characteristics of this research work underline that the two botanical varieties give different distinctive characters, due to the Fe content (80.05 vs. 1.42 mg/100 g d.s., for AHP and AHH wild-type flour samples, respectively), along with K, Ca, Mn, Ni and Cu, which are more abundant in the AHP samples. Furthermore, the Principal Component Analysis (PCA) was applied to the experimental dataset in order to classify and discriminate the samples, in relation to their similar botanical origin, but different for the color of the bloom. These results can be useful for the traceability of raw materials potentially intended for the production of auxiliary systems of pharmacological interest.

Health risk assessment of Cd, Cr, Cu, Ni and Pb in the muscle, liver and gizzard of hen's marketed in East of Iran.

The present study aimed to determine the average concentration of some metals, including cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and lead (Pb) in the chicken, hen's liver, and gizzard in the east of Iran. Estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and carcinogenic risk (CR) were calculated. In this cross-sectional study, fifty one samples including chicken, hen's liver and gizzard were obtained from Birjand, Iran. Measurement of Cd, Cr, Cu, Ni, and Pb was carried out by using an Inductively Coupled Plasma-Optic Emission Spectroscopy (ICP-OES). All of the measured metals were detected in 100 % of the samples. The metals had a different distribution pattern. The highest concentration of Cd and Cu was in the liver samples while the Cr and Ni had the highest levels in the chicken. Pb concentration was at the highest level in the gizzard. The least amount of Cr, Ni, and Pb was found in the liver while Cu had the least content in the muscle. EDI had an acceptable level, but the highest daily intake of all studied metals was through muscle. Cr had the highest THQ and it was more than one in the meat. HI in chicken was more than one. Liver and gizzard of hens had a neglectable HI. CR was neglectable in the case of both Cd and Pb, but it was considerable for Cr and Ni. The consumption of chicken in both adults and children may pose a significant health risk for consumers.

Sulfate of potash and yellow phosphorus to simultaneously remove SO2–NO and obtain a complete fertilizer

Flue gas includes SOX and NOX, and is considered to be a global issue due to its severe environmental problems. Hence, scientists have recently searched for new and efficient abatement techniques. The present study aims to simultaneously remove SOX and NOX, and obtain a complete N–P–K fertilizer by applying white/yellow phosphorus (P4) and sulfate of potash (SOP). We comprehensively investigated the most efficient parameters, which were determined to be a P4 weight of 0.5 g, stirring intensity of 1778 rpm, and temperature of 55 °C. We also compared the removal efficiency with the most efficient and recently identified absorbers. Moreover, we studied the simultaneous removal efficiency, with a deeper investigation of removing NOX only. The emulsion content was investigated using inductively-coupled plasma optical-emission spectroscopy (ICP–OES), an elemental analyzer, and ion chromatography (IC). The SOP content was investigated using X-ray diffraction (XRD). The results showed that the emulsion contained all of the elements required for a complete fertilizer. Finally, the process reaction mechanism, including the intermediate elements, was thoroughly identified. Considering the wide occurrence of SOX and NOX and the need for abatement, our simple, practical, energy-saving process provides a possible means for deriving useful byproducts as oppose to discarding them.

Physicochemical Characterization of Airborne Particulate Matter in Medellín, Colombia, and its Use in an In Silico Study of Ventricular Action Potential

Particulate matter (PM) is a complex mixture of particles that changes over time and from place to place; however, most PM is caused by the fuel combustion of motor vehicles and industry. PM is associated with acute and chronic illnesses, such as pulmonary and cardiovascular diseases. Medellin is one of the most polluted cities in Latin America. Therefore, the physicochemical characterization of its PM is necessary to understand its composition and effect on human health. In this study, PM was characterized by scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS) analysis, Fourier infrared spectroscopy (FTIR), inductivity-coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis (TGA) in order to evaluate its morphology and chemical composition. The SEM of the PM exhibited primary particles and agglomerates. The size of the particles ranged between 0.056 and 4.5 μm. The EDS revealed elements such as carbon, silicon, calcium, lead, and iron. Furthermore, carbon monoxide, carbon dioxide, and carbonyl and aliphatic functional groups were observed by means of FTIR. Additionally, weight losses associated with volatile matter and elemental carbon were identified in the TGA analysis. The TGA and FTIR confirmed the presence of fuel and lubricant traces. Subsequently, lead was selected among the most common components in the PM in order to conduct an in silico study into its effect on ventricular activity. Lead showed a pro-arrhythmic effect by shortening the duration of the action potential under normal electrophysiological conditions, which could be associated with cardiovascular diseases.

Heavy Metal Accumulation in Shrubs Used in Roadside Planting

&lt;p&gt;The aim of this study is to determine the shrub species which can be used as the biomonitor of air pollution originating mainly from the traffic and could provide the opportunity to increase the air quality in urban areas. To this end, Berberis thunbergii, Buxus sempervirens, Juniperus horizontalis, and Platycladus orientalis, mostly preferred species for roadside plantations, were chosen for the study. First, three regions with heavy traffic intensities were determined. Next, the levels of 4 heavy metals were examined by using Inductively Coupled Plasma–Optical Emission Spectrometry. The results obtained indicate that since the deposition of Cu and Zn is more in the leaves and barks of four species, these shrub species are more effective in the accumulation of Cu and Zn. Furthermore, the results of the study show that Platycladus orientalis is more effective in Cu and Pb accumulation, while Buxus sempervirens is more effective in terms of Ni and Zn accumulation. Determining high levels of traffic-originated heavy metals of Cu, Pb and Zn, particularly in the leaves of Platycladus orientalis in the city center indicates that air pollution is more intense in the city center and that Platycladus orientalis can be used as a biomonitor for traffic-originated air pollution.&lt;/p&gt;&#x0D;

Cobalt–chromium alloys fabricated with four different techniques: Ion release, toxicity of released elements and surface roughness

ObjectiveTo investigate the metal ion release, surface roughness and cytoxicity for Co–Cr alloys produced by different manufacturing techniques before and after heat treatment. In addition, to evaluate if the combination of materials affects the ion release. MethodsFive Co–Cr alloys were included, based on four manufacturing techniques. Commercially pure titanium, CpTi grade 4 and a titanium alloy were included for comparison. The ion release tests involved both Inductive Coupled Plasma Optical Emission Spectrometry and Inductive Coupled Plasma Mass Spectrometry analyses. The surface analysis was conducted with optical interferometry. Cells were indirectly exposed to the materials and cell viability was evaluated with the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) method. ResultsAll alloys showed a decrease of the total ion release when CpTi grade 4 was present. The total ion release decreased over time for all specimens and the highest ion release was observed from the cast and milled Co–Cr alloy in acidic conditions.The cast and laser-melted Co–Cr alloy and the titanium alloy became rougher after heat treatment. All materials were within the limits of cell viability according to standards. SignificanceThe ion release from Co–Cr alloys is influenced by the combination of materials, pH and time. Surface roughness is influenced by heat treatment. Furthermore, both ion release and surface roughness are influenced by the manufacturing technique and the alloy type. The clinical implication needs to be further investigated.

Improving manganese circular economy from cellulose by chelation with siderophores immobilized to magnetic microbeads

Manganese (Mn) contained in cellulose is partially responsible for an increased consumption of paper bleaching chemicals (like O2, H2O2), consequently diminishing the efficiency in pulp processing, darkening the pulp and deteriorating pulp quality. Usually, Mn in the paper industry is removed employing the environmentally critical EDTA. A greener alternative constitutes, however, the use of siderophores, high-affinity metal-chelating organic compounds that are produced by microorganisms to acquire metals (Fe and Mn among others), like desferrioxamine B (DFOB) or desferrioxamine E (DFOE). The use of native Mn-transporter proteins, like PratA, constitutes another possibility for Mn removal. The evaluation of utilizing siderophores or PratA for Mn removal from cellulose in a circular economy scheme is therefore essential. Firstly, Mn removal from cellulose was performed by immobilizing siderophores or PratA on magnetic beads (M-PVA C22). Secondly, the beads were incubated overnight with a 2% cellulose suspension, allowing Mn-ligand complex formation. Finally, cellulose suspensions were submitted for Mn quantification, employing either the TCPP [Tetrakis(4-carboxyphenyl)porphyrin] method, the PAN [1-(2-pyridylazo)-2-naphthol] method or the Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). When non-immobilized ligands were employed, a 31% Mn removal was achieved; when using immobilized ligands, around 10% Mn removal was obtained. Treated and untreated cellulose was analyzed by SEM and the Mn distribution between the solid and liquid phase was parameterized using adsorption isotherm models. This novel greener method proved to be feasible and easy, leading to potential improvements in the paper industry. Next research steps are to optimize Mn removal and quantify Mn recovery after ligand decoupling before scaling-up.

Developing a contamination susceptibility index for the Goreangab Dam in Namibia

The convenience and quality of life provided by dams is highly dependent on the quality of the retained water. Human intervention plays an important role in defining the quality of the retained water as expanding human populations have a large impact on the surrounding environment and the, quality of impounded water. The types and extent of human activities taking place in and around the dam will generally have an effect on the unique physical and chemical properties of water within the reservoir, thereby affecting the biodiversity and related functions thereof.Therefore, the need for comprehensive water quality assessment and reporting tools including contamination susceptibility indices cannot be overemphasized. The study thus aimed at developing a contamination susceptibility index for the Goreangab dam by evaluating the effects of anthropogenic activities on surface water quality through the analysis of the physico-chemical properties of the water column and sediments, an aquatic invertebrate evaluation and pollution risk assessment, using the Pollution Load and the wastewater presence, recreational impact, agricultural impact, size of the watershed, transportation avenues, industrial impact and vegetative ground cover, (WRASTIC) indices.Analytical experimental studies were used as references to methods employed in this research. Water, aquatic invertebrates and sediment samples were collected from 6 sampling sites, selected on the basis of their exposure to anthropogenic activity. The quality parameters investigated included dissolved oxygen, pH, total dissolved solids, chemical oxygen demand, temperature, electric conductivity and select heavy metals Pb, As, Fe, Zn, and Hg. Water and sediment samples were analysed using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and X-ray fluorescence (XRF) methods respectively. These were compared to the allowable limits stipulated in the Namibian Water Act (Act No. 54 of 1956). With the exception of TDS, Electric Conductivity and COD all other physical parameters recorded levels below the national set standard.Metal composition in the water column were all below the allowable limits, decreasing in the order Fe > Zn > Hg > Cd > As > Pb. The sampling stations upstream recorded higher average concentrations of metals in comparison to the downstream areas.The Pollution Load Index (PLI) results indicated deteriorating quality of soil sediments for all sampling stations, with higher deterioration upstream as these areas were privy to sewage and wastewater effluent. The aquatic invertebrate inventory and identification results categorised upstream Goreangab dam as a seriously modified habitat with very poor water quality whereas the downstream areas were found to be moderately modified. The average heavy metal concentrations were found to be below allowable limits for most of the sampling sites. Based on bio-monitoring and soil analyses results, there was indication of poor and deteriorating water quality at all sampling sites.The WRASTIC index indicated that the watershed was at high risk of contamination with a score of 51 and also identified five (5) of the sampling stations as risky areas serving as entry points for pollutants into the dam. The WRASTIC score is subject to a 3-year waver, indicating that the dam will be at a higher risk sooner as activity around the watershed continues to increase. The overall study results suggest that anthropogenic activity is a major factor in the contamination of the watershed and contributes greatly to its vulnerability. Regular screening of the Goreangab dam for sources of pollution will need to take place, along with continuous quality monitoring and assessment for the successful protection and restoration of the dam.

Effect of different doses of radiation on morphogical, mechanical and chemical properties of primary and permanent teeth\u2014an in vitro study

BackgroundRadiotherapy, applied to the head and neck region, can cause radiation side effects such as reduction of saliva and radiation caries. The aim of this study was to perform an in vitro assessment of the effects of radiation therapy on the morphological, mechanical, and chemical properties of primary and permanent teeth.MethodsOne hundred four extracted human teeth (52 impacted wisdom teeth, 52 primary molar teeth) were used. The teeth were divided into two parts in the mesiodistal direction. Of the 98 teeth, the vestibular sections were used for the vickers analysis and lingual sections were used for the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) analysis. The teeth in the experimental group were fixed to wax models. Each model had an equal number of teeth (n = 7). The doses were applied to the teeth for 6 weeks; 5 week days and 2Gy daily. After the radiotherapy was conducted weekly, a wax model was taken from radiation reception. Along with the elemental contents (Na, K, Mg, P, and Ca) of the teeth, enamel and dentin microhardness was evaluated, and SEM analyzes were performed on 6 teeth.ResultsRadiation caused a decrease in microhardness of enamel and dentin (p < 0.05). In the elemental analysis by ICP-OES, it was observed that there were decreases in all elements after 60Gy compared to the control group (p < 0.05). In the experimental groups, amorphous structures were encountered in SEM images.ConclusionsRadiation has negative effects on the teeth structure and additional studies are needed in this regard. This study indicates that radiotherapy patients are at a higher risk for dental caries.