Plasma Atomic Emission Spectrometry Method Research Articles

An electrochemical biosensor for the detection of sodium ions in serum based on Ce13d DNAzyme

In this study, a Ce13d DNAzyme-based electrochemical biosensor for the detection of sodium ions (Na+) in the serum was developed. The indium tin oxide (ITO) electrode was modified with Au gold nanoparticles (AuNPs), then immobilized with double-stranded DNA formed by thiol of substrate strand and enzyme strand bound via Au-S link. In the presence of Na+, the resulted Ce13d DNAzyme could preferentially bind Na+, and induced local folding of Ce13d to form a G-quadruplex-like structure, which enhanced binding ability to methylene blue (MB). By using the specificity of DNAzyme and change of its conformation, the quantitative detection of Na+ could be achieved. Thus, the developed sensing platform could identify Na+ with a linear response range of 10 nM-100 mM and a detection limit of 1.03 nM. The electrochemical biosensor also exhibited excellent selectivity for Na+ in the presence of five interfering ions, including K+, Cu2+, Mg2+, Zn2+ and Ca2+. Furthermore, the proposed biosensor showed satisfactory results for Na+ in serum sample analysis, which highly correlated with the inductively coupled plasma atomic emission spectrometry method. This work demonstrated a simple and reliable method for Na+ in serum, which opens the way for potential applications in disease diagnosis and environmental testing.

Influence of Hybrid Surface Modification on Biocompatibility and Physicochemical Properties of Ti-6Al-4V ELI Titanium.

Titanium-based materials are the most widely used materials in biomedical applications. However, according to literature findings, the degradation products of titanium have been associated with potential allergic reactions, inflammation, and bone resorption. The corrosion process of Ti-6Al-4V in the human body environment may be exacerbated by factors such as reduced pH levels and elevated concentrations of chloride compounds. Coatings made of biopolymers are gaining attention as they offer numerous advantages for enhancing implant functionality, including improved biocompatibility, bioactivity, wettability, drug release, and antibacterial activity. This study analyzes the physicochemical and electrochemical behavior of the Ti-6Al-4V ELI alloy subjected to PCL and PCL/TiO2 deposition by the electrospinning method. To characterize the polymer-based layer, tests of chemical and phase composition, as well as surface morphology investigations, were performed. Wetting angle tests were conducted as part of assessing the physicochemical properties. The samples were subjected to corrosion behavior analysis, which included open circuit potential measurements, potentiodynamic tests, and the electrochemical impedance spectroscopy method. Additionally, the quantification of released ions post the potentiodynamic test was carried out using the inductively coupled plasma atomic emission spectrometry (ICP-AES) method. Cytotoxicity tests were also performed. It was found that surface modification by depositing a polymer-based layer on the titanium substrate material using the electrospinning method provides improved corrosion behavior, and the samples exhibit non-toxic properties.

DEVELOPMENT OF APPROACHES TO THE ANALYSIS OF ELEMENTAL IMPURITIES IN TITANIUM DIOXIDE (BARIUM AND LEAD DEFINITION)

Relevance. Titanium dioxide (TiO2) is widely used in the pharmaceutical industry as a drug excipient (DE). Therefore, control of its content of ele-mental impurities (EI) plays an important role in ensuring the stability of quality and safety of drugs. The lack of harmonized pharmacopoeial require-ments for the content of EIs in TiO2, as well as the need for specialized validated methods of their analysis determine the actual task in the field of quality control of this substance. Research objective. This work is devoted to the development and validation of a method for the determination of barium and lead in TiO2 sub-stance. Material and Methods. The inductively coupled plasma atomic emission spectrometry (ICP-AES) method was used to determine the barium and lead content in the TiO2 substance. Acid extraction was used in the sample preparation process. All used reagents and materials were in accordance with pharmacopoeial requirements. A sample of TiO2 substance, manufactured by Venator Germany GmbH, Germany, was used as an object of study. Validation of the method was carried out in accordance with the requirements of GF RF for the following characteristics: specificity, linearity, LOQ, correctness, repeatability, intra-laboratory precision and range of the technique. Results. The method of barium and lead determination in TiO2 substance using ICP-AES demonstrates high accuracy and sensitivity. The results ob-tained during validation meet the acceptance criteria, which confirms the applicability of the technique for control of barium and lead content in TiO2 substance. Conclusions. A method for the determination of barium and lead impurities in TiO2 substance using the ICP-AES method and acid extraction during sample preparation has been developed. This approach enables the determination of barium and lead at the specification level (20 ppm and 5 ppm, re-spectively). The validation results meet the acceptance criteria for all characteristics investigated, confirming the ability to quantify barium and lead in the range of 50% to 150% of the specification level.

Determination of Ca, P, K, Na, and Mg in Australian Retail Pasteurised Milk Using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP OES)

A rapid and simple inductively coupled plasma atomic emission spectrometry (ICP OES) method was developed and validated for the determination of macroelements including calcium (Ca), phosphorus (P), potassium (K), sodium (Na), and magnesium (Mg) in Australian retail pasteurised milk. The milk samples were digested using the mixture of 70% HNO3 and 30% H2O2 (2 : 1, v/v) in an open‐tube digester block at 120°C for 4 h. The validated ICP OES method showed good linearity for all elements (R2 > 0.9993). The method limits of quantification (LOQ) for Ca, P, K, Na, and Mg were 19.85, 8.97, 100.8, 41.92, and 11.56 µg·g−1, respectively. Recoveries were in the range of 91.54–116.0%. Repeatability and interday reproducibility expressed as the relative standard deviation (% RSD) was below 5.0%. The contents of macroelements in 6 retail pasteurised milk samples were between 1099.32 and 1348.65 µg·g−1 (Ca), 914.01 and 1091.21 µg·g−1 (P), 1362.76 and 1549.74 µg·g−1 (K), 288.89 and 323.22 µg·g−1 (Na), and 97.62 and 110.57 µg·g−1 (Mg). Principal component analysis (PCA) revealed that retail pasteurised milk samples were distinctly separated into four groups on the first two principal components (PCs). The difference in the macroelement content between milk brands might be affected by milk regions.

Color-controlled nonstoichiometric spinel-type cobalt gallate nanopigments prepared by supercritical hydrothermal synthesis.

Spinel-type inorganic pigments with intensive color and chemical/thermal stability are showing extensive applications that could be further broadened by color manipulation and improvement of the material properties through nanosizing. In this study, we report the supercritical hydrothermal synthesis of nonstoichiometric spinel-type cobalt gallate nanoparticles (Co-Ga NPs) with controlled color. Without the conventional calcination procedure, NPs with greenish-blue, blue, and yellowish-green colors were synthesized from precursor solutions at pH 7, 9, and 11, respectively, with a low Co/Ga molar ratio of 0.25. X-ray diffraction, scanning/transmission electron microscopy, and inductively coupled plasma-atomic emission spectroscopy methods suggest that the products were spinel-type cobalt gallate NPs with high crystallinity and a nonstoichiometric composition. Based on an X-ray absorption fine structure investigation, the prepared nonstoichiometric Co-Ga NPs were found to have different cationic configurations from stoichiometric CoGa2O4 produced by a solid-state reaction during calcination. Meanwhile, the degrees of distortions at tetrahedral and octahedral sites in the NPs were evaluated by Raman spectroscopy. In particular, nonstoichiometric Co-Ga NPs with a blue color were prepared without calcination for the first time and were found to have lower tetrahedral cobalt occupancy but comparable octahedral cobalt occupancy and larger polyhedral distortions at tetrahedral sites when compared to calcined CoGa2O4. We also discuss strategies that could realize Co-Ga NPs with a more brilliant blue color using the present technique based on an investigation of the growth process.

Phytoremediation of Potential Toxic Elements by Native Tree Species in Mined- Spoiled Soils in Mátraszentimre, Hungary

Potential toxic elements, such as Arsenic (As), Cadmium (Cd), Copper (Cu), Lead (Pb), and Zinc (Zn) are commonly left behind after mining operation. Being non-biodegradable, these elements serve as source of contamination for the soil and water ecosystems and create hazards to human health. This research work evaluated the phyto extracting ability for potential toxic elements by four endemic tree species, such as Betula pendula (Birch), Carpinus betulus (Hornbean), Fagus sylvatica (Beech), and Salix caprea (Goat willow). These tree species are predominantly growing in an abandoned mining spoil sites in Mátra Mountains, Hungary. Plant and soil samples were collected in the field and analyzed using inductively coupled plasma-atomic emission spectrometry (ICP-OES) method. The soil was highly contaminated with heavy metals, such as Pb, As, and Zn which were 10 to 60 times more than the typical non-contaminated Hungarian soil. Among the trees evaluated, Carpinus betulus showed the highest potential for Pb dendroremediation, with a mean concentration value of 4071.67±45.71 mg kgˉ¹ dry weight in roots, 439.05±1.06 mg kgˉ¹ dry weight in stems and 92.53±0.73 mg kgˉ¹ dry weight in leaves. Betula pendula and Salix caprea bioaccumulated 475.575±2.219 and 395.97±1.43 mg kgˉ¹ dry weight of Zn in their leaf biomass. Both trees had a Bio-concentration Factor (BCF) value of greater than 1.0 but less than 10 which classified them as potential phytoextractors of Zn. Salix caprea gave the highest Translocation Factor (Tf) for Cd while Betula pendula gave the highest Tf for Zn.

Mineral Composition of Dietary Supplements-Analytical and Chemometric Approach.

There is a lack of data on the actual composition and effectiveness of beetroot-based dietary supplements. The research aimed to determine the profile of 22 elements (Na, K, Ca, Mg, P, Fe, As, Se, Zn, Cu, Ag, Co, Ni, Mo, Al, Mn, Sr, Cr, Ba, Li, Pb, Cd) in beetroot and its supplements by the microwave plasma atomic emission spectrometry (MP-AES) method. The analytical procedure was optimised and validated. The composition of both groups was compared, assessing compliance with the recommended daily doses for the chosen elements, and the health risk was estimated. Furthermore, chemometric analysis was applied. Beetroots constituted a significant source of elements, especially K, Na, Mg, Ca, P, in contrast to supplements which contained their negligible amounts except from iron-enriched products which provided notable amounts of Fe (38.3–88% of the Recommended Dietary Allowance for an adult male from 19 to 75 years old). Some products were significantly contaminated with toxic elements (As, Cd). Factor and cluster analyses were helpful in the differentiation of beetroot and its supplements in view of their type (vegetable, supplement, iron-enriched supplement), origin, type of cultivation (conventional, organic), and form (capsule, tablet) based on their mineral composition. The obtained results indicate the need for more stringent control of supplements, as they may pose a significant health risk to consumers.

An ICP‐AES method for routine high‐precision measurement of seawater Sr/Ca ratios to validate coral paleothermometry calibrations

AbstractA new inductively coupled plasma atomic emission spectrometry (ICP‐AES) method is presented for rapid and routine analysis of Sr/Ca molar ratios in seawater, with a long‐term precision of < 0.2%. It is an adaptation of a method widely employed for the analysis of coral aragonite Sr/Ca ratios in marine paleothermometry studies, which are based on the assumption that the seawater Sr/Ca ratio is constant in space and time. While prior studies have shown variations of up to 1% with depth, smaller variations at the ocean surface are generally accounted for via empirical, species‐specific calibrations of coral Sr/Ca vs. temperature. We found Sr/Ca variations in some coastal waters to be even larger, with distinct periodicity, complicating this approach. Although the high precision necessary for measurements of seawater Sr/Ca has previously relied on advanced mass spectrometry, long analysis times, and expensive isotopic spikes, our method uses more accessible instrumentation and is both time‐ and cost‐saving. The intricate composition of seawater, relative to coral aragonite solutions, requires an intensity ratio calibration technique combined with rigorous normalization to a suitable seawater standard. Key aspects of our method are discussed, including the choice of wavelengths, instrument parameters, accuracy, precision, and matrix effects. Special attention is given to the need for a certified seawater Sr/Ca reference standard, which does not presently exist. Analytical validation is provided by concurrent sharp gradients in Sr/Ca and δ18O, coinciding with the Florida landfall of hurricane Irma, as recorded at near‐daily resolution in a continuous seawater sample collected with an osmotic pump.

The Influence of ZnO Oxide Layer on the Physicochemical Behavior of Ti6Al4V Titanium Alloy.

Titanium and its alloys are characterized by high biocompatibility and good corrosion resistance as a result of the ability to form a TiO2 oxide layer. However, based on literature data it can be concluded that titanium degradation products, in the form of titanium particles, metal-protein groups, oxides and ions, may cause allergic, inflammatory reactions and bone resorption. The corrosion process of Ti6Al4V in the human body environment may be intensified by a decreased pH and concentration of chloride compounds. The purpose of this article was to analyze the corrosion resistance of the Ti6Al4V alloy, obtained by the selective laser melting method in a corrosion solution of neutral pH and in a solution simulating peri-implant inflammatory conditions. Additionally, the influence of zinc oxide deposited by the atomic layer deposition method on the improvement of the physicochemical behavior of the Ti6Al4V alloy was analyzed. In order to characterize the ZnO layer, tests of chemical and phase composition as well as surface morphology investigation were performed. As part of the assessment of the physicochemical properties of the uncoated samples and those with the ZnO layer, tests of wetting angle, pitting corrosion and impedance corrosion were carried out. The number of ions released after the potentiodynamic test were measured using the inductively coupled plasma atomic emission spectrometry (ICP–AES) method. It can be concluded that samples after surface modification (with the ZnO layer) were characterized by favorable physicochemical properties and had higher corrosion resistance.

Essential elements role in pathogenesis of occupational chronic lumbosacral radiculopathy in coal miners.

The problem of diagnosis in the early and preclinical stages of diseases is important in the prevention of occupational diseases and their complications, because this is the key to the timely initiation of treatment, the implementation of preventive measures. Chronic lumbosacral radiculopathy (CLSR) or low back pain (LBP) is one of the most common diseases in the structure of occupational pathology in Ukraine, which usually develops in those of working professions associated with physical activity, forced work posture, effect of high levels of general vibration, etc. The highest levels of occupational morbidity are recorded in the coal industry, which accounts for about 80% of occupational pathology in Ukraine. Above 1600 cases of CLRS are diagnosed annually in the country. A risk factor for the development of the CLSR is osteoporosis, which arises due to the impairment of quantitative and qualitative characteristics of bone tissue and is characterized by a decrease in its strength, animpairment of microarchitecture with a further increase in risk of fractures. One of the modern methods of assessing condition of bone tissue is determination of the content of macro- and trace elements (MaE and ME) in the biological environments of patients. Ca, Al, Mg, B, P are the most important in the formation and development of bone and connective tissue. To date, studies of bone tissue status in patients with CLSR of professional etiology have not been conducted (small in numbers). Goal – to determine the role of essential elements Ca, Al, Mg, B, P in serum and urine in the formation of occupational CLSR in miners. The research was conducted in 20 miners with CLRS (slaughterer, mining worker of a clearing face (MWCF), drifter) of coal mining industry of Donbass and Lviv-Volyn basins. The results were analyzed in two groups: І group consisted of patients with 10-15 years of work experience (n=10), II group with 16-32 years of work experience (n=10). The control group included 22 patients without pathology of the musculoskeletal system and connective tissue. The inductively coupled plasma atomic emission spectroscopy method (ICPAE) was used to determine the MaE and ME concentrations. The study revealed that the average serum aluminum (Al) concentration in miners with occupational CLSR (115.07 μmol/l) exceeded control group level (3.3 μmol/l) by almost 30 times (p<0.05). Serum boron (B) concentration in both age groups (25.90 μMol/l and 19.43 μMol/l, respectively) were lower than in the control (62.90 μMol/l), (p<0.05). The average serum calcium (Ca) concentration in patients with occupational CLSR (2.82 mmol/l) was 1.3 times higher than the same indicator in the control group (2.16 mmol/l), with a significant difference between the two age groups (p<0.05). It was revealed that the average level of phosphorus (P) in the urine of patients with occupational CLSR (19.0 mmol/l) significantly exceeded its content in patients of control group (11.96 mmol/l) (p<0.05). The concentration of Al in the urine of patients with CLSR in both age groups (1.26 μMol/l and 1.334 μMol/l, respectively) was higher that in control (0.85 μMol/l), (p<0.05). Reduction of Ca and Mg levels in the serum of miners in increasing work experience in harmful working conditions, exceeding average concentration of aluminum in patients' blood compared to the normative value and indicators of the control group patients was established.

Study on quality status of mineral medicine Calamina

In this paper, some quality problems of mineral medicine Calamina and calcined Calamina have been discussed after determination and analysis of the quality parameters of a large number of market samples, and the countermeasures are put forward. According to the XRD results, as well as the results of tests included in Chinese Pharmacopoeia(2015 edition), the authenticity of Calamina and calcined Calamina samples were identified. The content of zinc oxide in samples were determined by the method of determination in Chinese Pharmacopoeia. Individually, inductively coupled plasma mass spectrometry(ICP-MS), inductively coupled plasma atomic emission spectrometry(ICP-AES) and atomic fluorescence spectrometry(AFS) methods were used for the determination of impurity elements and harmful elements in Calamina and calcined Calamina samples. Four kinds of impurity elements of magnesium(Mg), iron(Fe), aluminum(Al), calcium(Ca) and five harmful elements such as lead(Pb), cadmium(Cd), arsenic(As), copper(Cu), mercury(Hg) were measured. The study showed that: ① Fake Calamina products on the market were overflowing; ② The mineral origin of the mainstream Calamina in the market is inconsistent with that stipulated in Chinese Pharmacopoeia(2015 edition); ③ The contents of harmful elements Pb and Cd in Calamina and calcined Calamina are generally higher, while the contents of harmful elements As and Cu in some inferior Calaminae are higher; ④ Parts of calcined Calamina were improperly or inadequately processed. In view of these quality problems, the countermeasures are put forward as follows: ① It is suggested that hydrozincite should be approved as the mineral source of Calamina, and be included by Chinese Pharmacopoeia; ② Strengthen the research on the specificity of Calamina identification methods to improve the quality control level; ③ Strengthen the research on the processing of Calamina, and formulate the limit standards for the content of Pb and Cd in Calamina; ④ Carry out research on the artificial synthesis of Calamina and calcined Calamina, in order to cope with the current shortage of Calamina resources and ensure the sustainable development of Calamina medicinal materials.

DETERMINATION OF COAL MICROELEMENTS BY INSTRUMENTAL ANALYSIS

In the mineral matter of coal there are microelements chemically bounded to organic matter or mineral impurities in various combinations that catalyzes the evolution / involution of a spontaneous combustion phenomenon as an accelerator in the oxidation reaction or which slows down these processes. Specialised literature analyzes the phenomenon of coal self-heating based on several theories of which we exemplify the theory of coal oxidation, the theory of pyrite and the theory of the microelements role in the process of coal oxidation. For the determination of these microelements in coal, the inductively coupled plasma atomic emission spectrometry method by means of which the mineral concentrations of hard coal and lignite samples were determined. The present paper proposes to perform a comparative analysis of the results obtained by laboratory determinations on samples taken from various coal basins (Valea Jiului, Motru, Jilt, Rovinari, Berbesti).

Crystal growth and structural characterization of Sm3+, Pr3+ and Dy3+-doped CNGG and CLNGG single crystals

Sm3+, Pr3+ and Dy3+-doped Ca3Nb1.6875Ga3.1875O12 - CNGG and Ca3Li0.275Nb1.775Ga2.95O12 - CLNGG crystals are of interest as solid-state laser materials emitting in the yellow-orange spectral range, especially for diode pumping due to their partially disordered nature. In this work, for the first time to our knowledge, single crystals of Sm, Pr and Dy-doped CNGG and CLNGG crystals were grown by the Czochralski method. For the doping of CNGG and CLNGG crystals, five new stoichiometric garnets were synthesised by solid-state reaction method: praseodymium-gallium-garnet (PrGG), dysprosium-gallium-garnet (DyGG) and praseodymium-lithium-niobium-gallium-garnet (PrLNGG), samarium-lithium-niobium-gallium-garnet (SmLNGG), and dysprosium-lithium-niobium-gallium-garnet (DyLNGG). Samarium-gallium-garnet (SmGG) was also sintered and used for the doping of Sm:CNGG crystal. Structural properties of sintered materials and grown crystals were investigated by X-ray diffraction and the chemical compositions of the grown crystals were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) method. The spectroscopic investigations of the grown crystals have shown that they are promising laser materials in the yellow-orange spectral range.

Geochemical Exploration for Gold and Associated Elements in the Granite Rocks at Wadi Al Marsad, Southwest Jordan

This study aimed to conduct a geochemical exploration for gold (Au) and associated elements from the granitoids rocks, to an attempt to outline the areas of abnormal concentration of gold and other elements such as As, Sn, Zn, Cu, Pb, Bi, Li, Be, Y, Nb, La, Ce, Mo, Fe 2 O 3 and TiO 2 . The geochemical anomalies areas were identified by using rock and Heavy Mineral geochemical methods. A total of 57 rock geochemical samples were collected from the granite, pegmatite, rhyolite dyke, quartz veins and ultration zone from the study area; and 37 Heavy Mineral (HM) geochemical panned concentrate samples were collected from the hillside sediments along the main valley and tributary from 30 cm depth and then sieved to 2 from the Northern part of Wadi El Marsad. Geochemical exploration for the abnormal concentration of gold and associated elements are used to identified the geochemical anomalies areas. The geochemical samples were chemically analyzed for their element components using Inductively Coupled Plasma Atomic Emission Spectrometry method (ICP-AES) and graphite furnace Atomic Absorption Spectrometer (AAS) method was used for the analysis of gold.. The results of geochemical analysis indicated the presence of gold in the study area; this result was considered abnormal for rock samples, while the gold was associated with vein, pegmatite and quartz veins. The presence of HM in the samples served as good indicators of gold in the area due to the detritus of gold-traces bearing rocks in the area. The Pearson’s correlation coefficients for the rock geochemical samples shows strong positive correlation was recorded for Au with As (r = 0.72), Cu (r = 0.78), Bi (r = 0.76), Y (r = 0.97), Nb (r = 0.94) and Ce (r = 0.50), respectively. The positive correlations for these metals revealed that the hydrothermal alterations affects the association of the metals in ultration zone, quartz veins and pegmatite dyke. The combination of both rock and HM concentrate samples showed three anomalous areas of gold. The interpretation of geochemical data for multi-elements of the rock samples shortlisted six geochemical anomalous areas and high concentration of Fe 2 O 3 , TiO 2 , As, Sn, Zn, Cu, Pb, Bi, Li, Be, Y, Nb, La, Ce and Mo. The HM samples indicated mineral concentration in the sulfide vein and pegmatite dyke at the sampled points; these elements are usually associated with sulfide minerals.

Source and Distribution of Dissolved Metal Ions in the Backwater Area of Pengxi River in Three Gorges Reservoir

This study uses the Gaoyang Lake section of the Pengxi River, the largest tributary on the northern bank of the Three Gorges Reservoir (TGR), as an example for exploring the distributions and dynamics of Ca, Zn, Fe, Cr, Pb, Cu, and Hg ions in the tributaries of TGR where the water level fluctuates due to dam regulation. Samples were taken 21 times, once every 17.3 days, at four sampling sites in Gaoyang Lake, which is in a perennial backwater zone of the Pengxi River, during one year from June 5, 2013 to May 29, 2014. At each sampling site, water samples were taken from the surface layer (0-0.5 m), middle layer, and bottom layer (0.5 m above the bed mud). During winter when the water was not stratified, the middle layer samples were taken at 1/2 depth, and when water was stratified in other seasons, the middle layer samples were taken from the thermal layer. Inductively coupled plasma atomic emission spectrometry (ICP-AES) and cold-vapor atomic absorption methods were adopted to determine the concentrations of the metals. Excel and SPSS were used for data analysis and Matlab for building 3-D prisms displaying concentration distributions of Hg ions in the high water level period (175 m, November-April in the ensuing year), sluicing period (May-middle June), low water level in the flooding season (145 m, June-August), and the storage period (September-November). The results provided the following observations ① Concentrations of Cr, Pb, Cu, Zn, and Hg ions were lower than those in Class Ⅲ of the water environment quality standard (GB 3838-2002). ② Cr, Pb, and Cu had high peak values during the storage and sluicing period, and the lowest values during the high water level period. Cr, Pb, and Cu were derived from the main stream of Yangtze, while Fe and Zn were from the Pengxi River locally. The concentration of Hg ions was affected by both the main stream and endogenous sources. As the water column stratified, metal ions did not mix among the stratified layers in Gaoyang Lake. ③ The conductivity was significantly lower during the high water level period than during other water level periods. The main material that affects the conductivity of Gaoyang Lake could be nonmetallic ions.

Determination of heavy metals in skin-whitening cosmetics using microwave digestion and inductively coupled plasma atomic emission spectrometry.

In this study, the determination of noxious heavy metals, cadmium (Cd), bismuth (Bi), mercury (Hg), titanium (Ti), lead (Pb) and metalloid arsenic (As) in skin-whitening cosmetics were examined using microwave digestion and inductively coupled plasma atomic emission spectrometry method. A complete digestion of cosmetics samples was achieved using a mixture of hydrofluoric acid/hydrogen peroxide/nitric acid. The quantification of the target compounds was done by standard addition method. The excellent quality parameters for instance, detection limits, As (4.6 ppb), Bi (7.9 ppb), Cd (0.45 ppb), Hg (3.3 ppb), Pb (3.8 ppb), Ti (4.3 ppb), linearity (r2 > 0.999) and run-to-run and day-to-day precisions with relative standard deviations <3% were obtained. The recovery rates for standard reference materials were found between 90 and 105%. The average concentration of heavy metals in cosmetics samples were in the range of 1.0-12.3 (μg g-1, As), 33-7097 (μg g-1, Bi), 0.20-0.6 (μg g-1, Cd), 0.70-2700 (μg g-1, Hg), 1.20-143 (μg g-1, Pb) and 2.0-1650 (μg g-1, Ti).

Corrosion resistance of PLGA-coated biomaterials.

The aim of the study was to determine the influence of PLGA bioresorbable polymer coating on corrosion resistance of metal biomaterial. Polymer coating deposited by immersion method was applied. Corrosion resistance of metal biomaterials (stainless steel, Ti6Al4V, Ti6Al7Nb) coated with PLGA polymer, after 90 days exposure to Ringer's solution was tested. The amount of metal ions released to the solution was also investigated (inductively coupled plasma-atomic emission spectrometry (ICP-AES) method). The surface of the samples was observed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Degradation of PLGA was monitored with the use of the 1H NMR spectroscopy and GPC (Gel Permeation Chromatography). The studies were carried out for non-sterilized (NS) and sterilized (S) samples. Application of the polymer coating causes a reduction of release of metal ions to the solution. Depending on metal substrate different course of destruction of polymer layer was observed. After 90 days of incubation in Ringer's solution polymer layer was highly degraded, however, the composition of copolymer (ratio of the comonomeric units in the chain) remained unchanged during the whole process, which suggests even degradation. The polymer layer reduced degradation kinetics of the metal substrate. Moreover, degradation process did not change surface morphology of metal substrate and did not disturb its integrity. The results obtained indicate that the applied polymer layer improves corrosion resistance of the alloys being investigated. Thus, the developed implants with bioresorbable coatings could be advantageous for medical applications.

Vinasse Dynamics on Soil Solution Under Sugarcane Crop: Inorganic and Organic Ion Analysis

Studies on ion movement in soil profiles associated to the application of vinasse are scarce. The objective of this study is to assess the quantity of inorganic and organic ions in the profile of the soil under sugarcane. The study was realized in a commercial sugarcane cultivar in the municipality of Ponta Pora, MS, Brazil in the harvest year of 2010/2011. The soil in the experimental area was classified as Haplorthox clay. The experimental design was randomized blocks, with four repetitions, two depths, and four harvest periods, after application of a 350 m3 h−1 vinasse dosage. Twenty-four soil solution extractors were installed at a distance of 4 × 4 m from each other in the areas under vinasse treatment. Vinasse was chemically characterized by the inductively coupled plasma atomic emission spectrometry method. The extracted solution samples were determined for ionic chromatography. Elevated concentrations of lactic, butyric, citric, tartaric, succinic, formic, and acetic acids were found up to 1 m of depth up to 29 days after application. After 63 days, no traces of those anions were found in the soil. There was a rise in nitrate and a decline in the content of chloride and sulfate.

A Sensitive Sensor for trace Hg2+ Determination Based on Ultrathin g-C3N4 Modified Glassy Carbon Electrode

This work reports a sensitive sensor for the electrochemical determination of trace mercury (Hg2+) by employing ultrathin graphitic carbon nitride (utg-C3N4) nanosheet as enhanced sensing platform. The utg-C3N4 nanosheets were obtained by exfoliating the bulk g-C3N4, which was synthesized via a thermal polycondensation process. The as-prepared samples were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM), which confirmed graphite-like structure with thickness of about 8nm. The g-C3N4 nanosheets can be easily attached on the surface of glassy carbon (GC) electrode free of any film-forming agent. It was found that Utg-C3N4 modified GC electrode showed enhanced electrochemical response to Hg2+ in comparison with bulk g-C3N4, which could be ascribed to the strong affinity between utg-C3N4 and Hg2+ through its NH and NH2 groups. This allows detection of Hg2+ in aqueous solutions with high sensitivity and selectivity. Under the optimized experimental conditions, the anodic stripping voltammetric (ASV) currents are linearly responsible to Hg2+ concentrations in the range of 0.1–15μg/L with a detection limit of 0.023μg/L (S/N=3). The sensitivity of the as-constructed sensor is about 6.8μA(μg/L)−1cm−2. In addition, the proposed sensor was applied in determining Hg2+ in practical samples and the results are comparable to those obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) method.

Utilization of modern analytical techniques for the analysis of household generated greywater samples*

Detailed analysis of household generated greywater (GW) samples is an essential task for the design of treatment systems before reuse. In this paper modern analytical methods will be discussed, which were applied to determine the ionic and elemental concentration of different GW samples. Ion chromatography (IC) and Microwave plasma atomic emission spectrometry (MP-AES) methods were used to spoor the composition of GW samples. It was shown that from the IC results and from calculated parameters (Na ee% and SAR) the application of raw or treated GW flows for irrigation is controlled. According to the elemental concentration, GW samples from laundry/kitchen sink and dishwasher proved to be the most contaminated compared to drinking water, while the concentration of the measured elements did not elevate as significantly in GW samples from shower/bathtub.