Emission Spectroscopy Method Research Articles

ANALISIS KANDUNGAN MINERAL (KALSIUM, KALIUM,FOSFOR) PADA KULIT PISANG KEPOK DAN PISANG AMBONDENGAN METODE MPAES

Banana is one of the most abundant horticultural commodities in Indonesia. Apart from the fruit, banana peels have great potential to be utilized because they contain various minerals that are beneficial to the body, such as calcium, potassium, and phosphorus. However, the utilization of banana peels is still very low because they are often considered as waste. This study aims to analyze the mineral content of kepok and ambon banana peels using the Microwave Plasma Atomic Emission Spectroscopy (MPAES) method. The study was conducted qualitatively and quantitatively. Qualitative analysis involved flame test and precipitation reaction to detect the presence of minerals, while quantitative analysis used MPAES instrument to measure mineral content. Qualitative results showed that kepok and ambon banana peels contained calcium, potassium and phosphorus. Quantitatively, kepok banana peels have an average calcium content of 2,568.7 mg/kg, potassium 5,237.6 mg/kg, and phosphorus 429.13 mg/kg. Ambon banana peel contains an average of 2,095.3 mg/kg calcium, 4,216.3 mg/kg potassium, and 177.43 mg/kg phosphorus. Differences in mineral content were analyzed using Paired sample T-Test and Wilxocon which showed significant differences in calcium and phosphorus levels between the two types of banana peels, while potassium levels showed no significant differences. The results of this study indicate the potential of banana peels as a source of minerals for nutritional supplements and pharmaceutical products. Utilization of banana peels can support organic waste management and increase the added value of banana production.

Interactions Between Toxic Metals and Serum Micronutrient Level in Auto-mechanics in Ibadan Metropolis, Nigeria: a Pilot study.

Auto-mechanics who often work without safety measures are vulnerable to the harmful effects of toxic metals like lead (Pb) and cadmium (Cd). These toxic metals exert their deleterious effect by interacting with the micronutrients at their primary site of action. This study aimed to investigate the effects of toxic metal exposure on serum micronutrient levels of auto-mechanics in Nigeria. This case-control study involves 60 participants aged 18 to 45years. The control group consists of 30 healthy male staff of University College Hospital Ibadan, Nigeria. The test group consists of 30 male auto-mechanics recruited from their workshops in the Bodija and Olodo areas of Ibadan, Nigeria. Blood lead (Pb), cadmium (Cd), plasma iron (Fe), zinc (Zn), selenium (Se), manganese (Mn), magnesium (Mg), and calcium (Ca) were quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES) method. Results show that systolic and diastolic blood pressure (SBP and DBP) and plasma levels of Pb and Cd were significantly higher in the auto-mechanic group when compared with control, while there were significantly lower levels of micronutrients: Fe, Zn, Mn, and Se when compared with control (p < 0.05). The plasma levels of Ca and Mg were not statistically different in the two groups. Also, there was a significant negative relationship between Cd and Zn (r = - 0.38, p = 0.001), a weak positive relationship (r = 0.46, p = 0.001) between Pb and SBP, and a weak non-significant negative relationship between Pb and Se (r = 0.4, p = 0.11) in the auto-mechanics. The chronic exposure to Pb and Cd in auto-mechanics is associated with elevated blood pressure and reduced micronutrients levels which can impact negatively on their health.

Оцінка токсичної дії ультрадисперсних частинок порошків феромарганцю і феросилікомарганцю на організм щурів

Introduction. Alloys of iron and manganese (ferroalloys) are traditionally used in metallurgy in the production of steel and various types of cast iron. One of the largest ferroalloy enterprises in Europe operates in Ukraine — the Nikopol Ferroalloy Plant, which produces more than 11% of the world volume of ferroalloys and employs more than 7,500 workers. Industrial production and use of ferroalloys contribute to the entry of their components into the production environment and affect the health of workers. It is known that asthenia, disorders of nervous system and cases of bronchial asthma were registered in workers engaged in ferromanganese melting. There are few data on the effect of ferrosilicomanganese on the human organism. Therefore, the study of the peculiarities of the toxic effect of ferroalloy powders — ferromanganese and ferrosilicomanganese on the organism is a relevant issue for occupational hygiene and industrial toxicology. Aim. Investigation of the peculiarities of the toxic effect of ferromanganese and ferrosilicomanganese powders on the body of rats after a single intratracheal administration during dynamic observation. Materials and Мethods. The experiment was performed on male Wistar rats with an initial body weight of 160–180 g. Suspensions of ferromanganese and ferrosilicomanganese powders in distilled water were administered once into the trachea of animals anesthetized with sodium thiopental at a dose of 50 mg of powder (1/100 LD50) per kg of rat body weight. Control rats were similarly administered 1 ml of distilled water. After administration (in one week, one month and three months), the content of iron, manganese and silicon in the blood of control and experimental rats was determined using the method of atomic emission spectrometry with inductively coupled plasma with the Optima 2100 DV device. Biochemical parameters were determined in all groups of rats (activity of ALT, AST, ALP enzymes; glucose, uric acid, total cholesterol, triglycerides, iron content, serum total iron-binding capacity (TIBC) and percentage of serum iron saturation (TfS), indicators of non-specific natural immunity (phagocytic and bactericidal activity of blood neutrophils, the level of circulating immune complexes (CICs)). Statistical analysis of the data was performed using Microsoft Excel 2007. Results. A single administration of a suspension of ferroalloy powders into the trachea of rats led to an increase in the content of Fe and Mn in the blood, in particular of the Fe content after the administration of ferromanganese and ferrosilicomanganese at all observation periods, while an increase in the level of Mn was detected after one month. The content of Si in the blood of rats of both experimental groups during the experiment was at the level of control values. It was established that an increase in the Fe content in the blood of experimental rats caused disruptions in its metabolism (a decrease in blood TIBC and an increase in the TfS percentage). 3 months after the administration of the powders, an increase in the activity of enzymes (ALT, AST, and ALP) was determined in the blood serum of both experimental groups of rats, as well as an increase in the content of uric acid, which may indicate damage to liver cells and the development of the inflammatory process. With the administration of both ferroalloys, a decrease in the phagocytic function of blood neutrophils and an increase in the formation of reactive oxygen species, an increase in the levels of low- and high-molecular weight CICs in the blood serum, especially one month after the administration, were determined, which indicates the activation of the humoral link of non-specific natural immunity against the background of a violation of the phagocytosis process. Conclusion. The established changes in biochemical and immunological indicators testify to the existing toxic effect on the body of ferromanganese and ferrosilicomanganese powders after their single administration into the trachea, and are caused by an increase in the content of Fe and Mn in the blood of experimental rats. The most pronounced changes were detected one month after the administration of both powders. More adverse effects on the body of experimental rats were caused by ferromanganese powder, the particles of which were smaller. Keywords: ferromanganese, ferrosilicomanganese, ultra disperse particles, toxicity.

Ultrafine industrial aerosol as an occupational risk factor for sintering industry workers

Aim. Assessment of the physicochemical characteristics of suspended particulate matter of the ultrafine range present in the air of the working area of the sintering factory of a metallurgical plant. Materials and methods. The assessment and analysis of the physicochemical parameters of ultrafine particles were carried out in different areas of the sintering factory of the metallurgical plant. The parameters were measured using a portable scanning spectrometer Nanoscan 3910 (USA). The chemical composition of the suspended particulate matter was determined by the method of optical emission spectrometry with inductively coupled plasma (OES-IZP) using the device “Ortima 2100 DV” (PerkinElmer, USA). Results. It was estimated that the concentration of suspended particulate matter of ultrafine size in the main part of the sintering machine ranged from 3.02 × 104 to 3.12 × 104 per cm3, in the tail part of the sintering machine – from 5.09 × 104 to 7.59 × 104 per cm3, in the sintering machine control room No. 1 – from 2.06 × 104 to 2.38 × 104 per cm3, in the workers of the control group – from 1.43 × 104 to 1.73 × 104 per cm3. The quantitative concentration of suspended particulate matter by individual sizes at all workplaces of the sinter plant workers compared to workers of the control group had a significant difference. Values of the total surface area and surface volume of suspended particulate matter of the nano-sized range had their maximum in the tail part and near the head of the sintering machine, the lowest values were recorded around the control room and among the employees of the plant management department. The highest mass concentration of ultrafine particles was recorded in the tail part of the sintering machine (22.55 μg/m3 to 508.35 μg/m3), which is associated with a significant amount of suspended particulate matter of a larger size (≥115.5 nm). The chemical composition of the particles of the ultrafine range included aluminum, calcium, iron, magnesium, manganese, silicon, and phosphorus, which is explained by the specifics of the technological process, and the exceeding of the hygienic standard was observed for calcium, silicon and phosphorus. Conclusions. It was established that during the sintering of the agglomerate in the agglomeration compartment, many suspended particles of the ultrafine range are formed. They included aluminum, iron, manganese, magnesium, silicon, phosphorus, and calcium. Significantly higher values of the number, mass concentration, surface area and surface volume of suspended particulate matter were determined at the workplaces of sintering factory workers, which had a statistically significant difference compared to the workers of the control group.

Organosilicon Polymeric Acetylene Derivatives: X-Ray Spectral Study and Quantum-Chemical Calculations

The atomic and electronic structure of two organosilicon polymers [–Ph2Si–(C≡C)2–]n (P1) and [–Ph2Si–(C≡C–C≡C)2–]m (P2) (where Ph — is phenyl group) of acetylene and diacetylene types by methods of density functional theory and X-ray emission spectroscopy. The interpretation of X-ray emission SiKβ1-spectra of these polymers was carried out based on an analysis of the distribution of partial electronic states obtained from quantum chemical calculations. Quantitative characteristics of the parameters of the chemical interaction of atoms, such as populations, natural charges, and electronic configurations in the studied polymers, were obtained based on the analysis of hybrid natural bond orbitals. The obtained values of the natural bond orbitals polarization coefficients indicate that the electron density is localized predominantly on carbon atoms. The electronic configurations for carbon atoms in different fragments differ significantly. For C atoms of ethynyl (diethynyl) fragments, they are close to linear σ-bond with sp1.03 (P1) and sp0.95 (P2) configurations, while for C atoms of phenyl fragments it is sp2.42, intermediate between sp2 and sp3 configurations. The natural charges on Si in both polymers are almost the same: +1.58e, +1.59e, while the natural charges on the carbon atoms of the diethynyl group decrease in comparison with the charge on the carbon atom of the ethynyl group from –0.42e to –0.36e.

Selection of internal standards for the determination of rare earth elements by atomic emission spectrometry with microwave plasma

The method of atomic emission spectrometry with excitation spectra in microwave plasma was used to determine the composition of lanthanum sulfide crystals and europium-doped gadolinium oxide, as well as elements in the melt (tin, boron, and lithium). Calibration curves for rare earth elements are nonlinear and do not provide the required accuracy of analysis. To reduce errors and linearize the calibration curves, the internal standard method was used. Molecular ions N2, N2+ and OH did not correct for changes in plasma conditions and inter-element effects. Internal standard elements were selected based on the proximity of the first ionization potential to the analytes, considering Ba, Al, Ga, and In. The use of these elements as internal standards allowed the linearization of calibration curves, achieving an analytical accuracy of 95−105%. The found total mass of the elements was 97−103% of the sample mass, with accuracy confirmed by the method of standard additions.

A novel plasma optical emission spectroscopy method with neural network model for improving the accuracy of plasma diagnostics in low-temperature xenon plasma

A novel plasma optical emission spectroscopy method with neural network model for improving the accuracy of plasma diagnostics in low-temperature xenon plasma

Direct One-Stage Plasma Chemical Synthesis of Nanostructured Thin Films of the System β-Ga&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-GaN of Different Composition

For the first time, nanostructured thin films of the β-Ga2O3−GaN system were obtained by plasma chemical deposition from the gas phase (PECVD) on c-sapphire substrates. High-purity metallic gallium, as well as high-purity gaseous nitrogen and oxygen were used as sources of macro components. The low-temperature nonequilibrium plasma of an inductively coupled HF (40.68 MHz) discharge at a reduced pressure (0.01 Torr) was the initiator of chemical transformations between the starting substances. A mixture of oxygen and nitrogen was used as a plasma-forming gas. The plasma chemical process was studied using the optical emission spectroscopy (OES) method. The obtained thin films of the β-Ga2O3−GaN system with a GaN phase content of 2 to 7% were characterized by various analytical methods.

Neural network cognitive analysis of accumulation metals by marigold

The article presents the results of studies to assess the effect of humic acids, taken at a concentration of 250 ppm, on the process of induced phytoextraction of heavy metals from soils selected near Norilsk. Phytoxtraction was carried out by different types of marigold plants: Tagetes patula and Tagetes erecta. The studies were carried out in greenhouse conditions under controlled spectral illumination (light culture). The duration of the experiment was 21 days. A short vegetation period was chosen based on the conditions of a short summer period typical for this region, where it is more rational to keep records of the systemic removal of toxicants from contaminated soils by several cycles of their sowing/cutting per season, already at the juvenile phase of ontogenesis. For elemental analysis, the method of atomic emission spectrometry with inductively coupled plasma was used. To assess the level of efficiency of metal accumulation, the authors developed and used the original computing neural network CompNN, which allows calculating the cognitive significance index (CSI) based on empirical data on the accumulation of toxicants, both in shoots and roots of plants. The results of the study showed that the introduction of an organic additive in the form of humic acids into the soil led to inhibition of the growth of the above-ground part of T. patula. As for T. erecta, the rate of accumulation of green plant biomass did not change when humic acids were added. The decrease in the biomass of shoots of T. patula plants is explained by an increase in the accumulation of metals in them by an average of 91.6% for the variants. The content of metals in the shoots of T. erecta under the influence of humic acids, on the contrary, decreased by 17.3% on average. A similar result was observed in relation to the root zone: the trend of change in the fixation of metals for both plant species here was 40.8 and 10.8%, respectively. Calculation of CSI indices also showed that the addition of humic acids in T. patula increases the intensity of metal accumulation from the soil in its biomass in all variants, while in T. erecta, on the contrary, it decreases. The performed cluster analysis demonstrated the fixation of metals in the main buffer zone of plants, and also made it possible to isolate nickel into a separate homogeneous series. With regard to the distribution of this element in the shoots by variants, experience has shown that it has demonstrated here the proximity of convergence with copper. The correlation coefficients of their accumulation with the CSI index in the shoots of both plants were r = 0.82; 0.87 for Cu and r = 0.87; 0.83 for Ni. The proximity of these values indicates the priority nature of the accumulation of these metals in the plant biomass of marigolds, and also characterizes the manifestation of certain interactions between them in contaminated soil by the type of antagonism or synergism.

Potentially hazardous elements in atmospheric precipitation during the warm season (May–September) of 2019 in Moscow

Atmospheric precipitation acts as a significant pathway for pollutants from the atmosphere to the Earth’s surface, and analyzing urban precipitation data on intensity, fallout regime, transfer patterns, and solid particle content helps identify pollution sources. For the first time in the Moscow megacity, the levels of soluble forms of potentially hazardous elements (PHEs) in atmospheric precipitation were studied during the whole summer season of May–September 2019. The concentrations of Al, As, B, Ba, Be, Bi, Cd, Ce, Co, Cu, Fe, La, Li, Mn, Ni, P, Pb, Rb, Sb, Sn, Sr, and Zn were determined using inductively coupled plasma mass spectrometry and atomic emission spectroscopy methods. The research underscores the crucial role of atmospheric precipitation in washing PHEs out of the atmosphere. In May and September, concentrations of PHEs surpass the warm-season average. Notable contamination in May stems from elevated traffic during vacations, extensive burning of plant debris and wood, and pollen transport. Summer months are characterized by reduced forest and agricultural fires, traffic, and increased vegetation, leading to lower PHE concentrations, especially in July, with typical amount of precipitation contributing to pollutant dispersion. Elevated PHE levels in September are observed due to increased traffic load, biomass burning, and the expansion of unvegetated soil areas. Rainwater is enriched with Sb, Pb, Cd, Zn, Cu, B, Bi, P, and Sr, sourced from vehicle emissions, soil particles, industry, construction dust, biomass burning, and forest fires. Moderate enrichment with Ba, Mn, Ni, Co, and Sn also occurs episodically. Regression analysis highlights solid particles’ role as a major PHE source in rainwater, with the longer antecedent dry periods and the higher acidity level of rain intensifying the accumulation of PHEs. Long-range transport plays a lesser role, with Southern and Northern Europe, Western Siberia, and the central part of European Russia contributing meaningfully.

Study of a Helicon Plasma by Emission Spectroscopy Methods

Study of a Helicon Plasma by Emission Spectroscopy Methods

Construction of Multi-Channel Radio Frequency Plasma Jet System in Atmospheric Pressure and the Diagnosis of Plasma Parameters and I-V Characteristics

In order to produce cold plasma at atmospheric pressure, a multi-channel RF, of (1, 2, 3, and 4 MHz) frequencies, plasma jet system is developed using argon as the working gas. This system consists of two parts, a multi-channel power supply (of a power of 100 W) and a plasma jet. A strong electric field is created that ionizes and excites argon ions. The I-V characteristics of the system and the electron temperature and density for different powers (20, 50, 70, and 80 W), gas flow rates (10, 20, 30, and 40 sccm) (standard centimeter cubic per minute) at different frequencies (1, 2, 3, and 4 MHz) are studied, using the optical emission spectroscopy method. This system can be used in medical applications and material treatment with high efficiency.

Development and Validation of an ICP‐OES Method to Determine Extractable and Leachable Metals in HDPE (Plastic) Pharmaceutical Packaging Material

ABSTRACTThe safety and effectiveness of pharmaceutical medicines depend heavily on extractables and leachables. Patients may be adversely affected by contaminants that enter drug products through packing materials. As a result, regulatory organizations like the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) have set standards and regulations for evaluating and managing extractables and leachables. Characterizing the packing materials, carrying out extraction experiments and checking the extracted solutions for contaminants are all parts of this research. As part of the process for approving new drugs, regulatory agencies make use of these data. In present work, an inductively coupled plasma optical emission spectroscopy (ICP‐OES) method is developed and validated for quantifying trace elements from a high‐density polyethylene (HDPE) packaging material. The approach delineated in accordance with United States Pharmacopoeia (USP) &lt;661.1&gt; and &lt;661.2&gt; for the comprehensive analysis of 16 metallic elements including aluminium, arsenic, cadmium, chromium, cobalt, lead, mercury, nickel, titanium, vanadium, zinc, zirconium, barium, manganese, calcium and tin is applicable for evaluating the efficacy of packaging materials. The method detection limits (MDLs) complied as per USP 39‐NF 34 &lt;661.1&gt; along with relative standard deviations (RSDs) obtained were ranging from 0.3% to 3.1% and recoveries of all elements spiked at two different trace levels in HDPE samples were within 97%–110%, providing sensitive, accurate and reproducible methodology.

Analysis of sulfur in soil and plant digests using methane as a reaction gas for ICP-MS

Quantitation of sulfur (S) is vitally important for analysis of agricultural soil and plant samples due to the requirement of S in living organisms. Although inductively coupled plasma mass spectrometry (ICP-MS) is a commonly used and robust instrument for multi-elemental detection, S is usually analysed by ICP-optical emission spectroscopy (OES) since S quantitation poses a particular challenge for ICP-MS due to interferences on all S isotopes. The requirement for analysis by two instruments increases time and cost for sample analysis, hence analysis by one instrument is desirable. The use of reaction gases in ICP-MS can improve the performance by shifting S to a mass for detection where no interference is present. This work explored the potential of methane as a reaction gas for analysis of S in soil and plant samples to give users an alternative option to oxygen. The product ion clusters CH2SH+ were monitored (m/z 47 and 49 on ICP-MS and with mass shift of +15 from Q1 → Q2 using 32 → 47 and 34 → 49 on triple quadrupole ICP-MS). As expected, triple quadrupole ICP-MS performed better than single quadrupole ICP-MS containing a reaction cell due to the ability to preselect the m/z of choice and remove ions that may react with methane in the reaction cell. The method detection limit (MDL) was 150 mg kg−1 S for plants and 53 mg kg−1 S for soils which is fit for requirements. This is the first-time methane has been reported as a reaction gas for analysis of S and shows promising results for agricultural samples when using a triple quadrupole ICP-MS. Results compared well to those obtained via the more commonly used ICP-optical emission spectroscopy (OES) method with results <20 % for all samples. Interlaboratory comparison samples were within 2 Z-scores of the consensus mean. In the absence of ICP-MS/MS, Q-ICP-MS with detection of cluster m/z 47 was deemed to be suitable for detection of S in plant samples, with acceptable MDL (250 mg kg−1 S), acceptable precision (<20 % RSD) and <20 % variation to the reported ICP-OES result.

Elemental tracer determination and modeling for geographical origin designation of sweet oranges

Sweet oranges have long been an integral part of global health and culinary practices, offering a wealth of nutrients and bioactive compounds. Ensuring the authenticity of these citrus fruits is essential for maintaining consumer confidence, promoting transparency in sourcing, and protecting producers' reputations in the marketplace. In this study, we explored the feasibility of using multi-element profiling combined with pattern recognition algorithms to trace the origin of sweet orange samples. To achieve this, we employed an optimized microwave plasma atomic emission spectroscopy (MP-AES) method to analyze the elemental composition (Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, and Zn) of 183 orange samples from four production regions in northeastern Argentina. Support vector machine (SVM), random forest (RF), and gradient boosting tree (GBT) models were then built using the collected data to identify elemental tracer's indicative of origin. Based on a comprehensive evaluation of overall accuracy, receiver operating characteristic (ROC) curves, and area under the curve (AUC), the GBT model demonstrated the best classification performance, achieving a 96.5 % correct prediction rate on test samples, as confirmed by the ROC curve (AUC = 0.973). Consequently, this approach provides compelling evidence for the potential utility of MP-AES combined with supervised modeling to determine the geographic origin of sweet oranges produced in Argentina, thereby contributing to consumer protection against fraud.

Effect of Microwave Antenna Material and Diameter on the Ignition and Combustion Characteristics of ADN-Based Liquid Propellant Droplets

Microwave-assisted ignition is an emerging high-performance ignition method with promising future applications in aerospace. In this work, based on a rectangular waveguide resonant cavity test bed, the effects of two parameters (material and diameter) of the microwave antenna on the ignition and combustion characteristics of ADN-based liquid propellant droplets were investigated using experimental methods. A high-speed camera was used to record the droplet combustion process in the combustion chamber, the effect of the microwave antenna on the propellant combustion response was analyzed based on the emission spectroscopy method, and finally, the loss of the microwave antenna was evaluated using a scanning electron microscope. The experimental results show that the droplet has the lowest critical ignition power (179 W) when the material of the microwave antenna is tungsten, but the ignition delay time is higher than that of copper. A finer diameter of microwave antenna is more favorable for plasma generation. At a microwave power of 260 W, the ignition delay time of the droplet with a microwave antenna diameter of 0.3 mm is 100 ms lower than that of 0.8 mm, which is about 37.5%. In addition, this study points out the mechanism of microwave discharge in the droplet combustion process. The metallic microwave antenna not only collects the electrons escaping from the gas discharge, but also generates a large amount of metallic vapor, which provides charged particles to the plasma. This study provides the possibility for the application of microwave-assisted liquid fuel ignition.

Experimental Research on the Study of Мéntha Piperíta Makro- and Microelement Composition Growing in Goris, Syunik Region

The purpose of our work was to study the qualitative and quantitative composition of the mineral elements of peppermint (Méntha piperíta) leaves. The relevance of the study is revealed by the fact that, though some trace elements in low concentrations are necessary for plant growth, their excess can lead to plant death. This effect depends both on the nature of the element and on the type of plant. To achieve this goal, we used the method of optical emission spectroscopy with inductively coupled plasma on an Agilent 5110 ICP-OEC equipment. The object of research was the dried aerial part of peppermint (Méntha piperíta) growing in Goris region of Armenia. The content of 30 elements was determined, for five of which the biological absorption coefficient is greater than unity. This means that these elements accumulate in plants. These include strontium and molybdenum, which are toxic elements. Based on the data presented, it is certainly necessary to control the maximum permissible concentrations of molybdenum and strontium in peppermint (Méntha piperita) collections before using it in cooking and for the creation of medicinal products.

Application of ICP-OES for determination of mercury species in environmental samples

Direct determination of mercury species in real environmental samples is challenging due to their trace concentrations and low ionisation energy. In this investigation, a microwave-assisted and aqua regia digestion method is proposed for the analysis of trace inorganic mercury. Measurements were performed using inductively coupled plasma optical emission spectroscopy (ICP-OES) method in soil, digestate and waste samples. The detection limits of the proposed method were found to be 0.03 and 0.115 mg/kg for mercury at 184.9 and 194.2 nm, respectively. The accuracy of the method with respect to the systematic and constant errors was confirmed by the analysis of certified reference material (CRM) (&amp;gt; 95 % recovery with &amp;lt; 15 % relative standard deviation RSD). The method was successfully applied for the determination of mercury in solid wastes listed in the Decree on Burdening of Soil with Waste Spreading and the Decree on the Treatment of Biodegradable Waste and the Use of Compost or Digestate in the Republic of Slovenia (Official Gazzette of the Republic of Slovenia, No. 34/08 and 61/11 and No 99/13, 56/15 and 56/18).

Rapid determination of germanium in lignite coal and coal-related solid byproducts by graphite furnace digestion inductively coupled plasma emission spectroscopy

This study developed a rapid and efficient graphite furnace digestion combined with inductively coupled plasma emission spectrometry (ICP-OES) method, enabling precise quantification of germanium (Ge) in coal and various coal-derived metallurgical byproducts across a broad concentration level (∼ppm-n%). The graphite furnace digestion conditions were examined intensively as a function of the acid amounts of HNO3 and HF (5–10 mL), temperature (80–180 °C), time (1–5 h), and acid drive methods (H3BO3 neutralization versus heating). Coal references including SARM 19, SARM 20, NIST SRM 1632e, and fly ash standard NIST SRM 2689 were tested. The optimum recovery of germanium was obtained when the HNO3 dosage, HF dosage, solid sample mass, temperature, and duration time were 10 mL, 5 mL, 0.1 g, 80 °C and 1 h. Agreement of 95.15–96.54 % between the measured and certified value was obtained under the optimum conditions. The spiked recovery was 103.23–103.54 %, indicating the matrix-analytes interactions were negligible. Boric acid neutralization reduced the recovery rates to 47.2–49.3 % and was not be appropriate for driving HF. The optimal spectral line for determining Ge is at a wavelength of 265.117 nm, at which the limit of detect and the limit of quantification were 0.46 μg L−1 and 1.53 μg L−1, respectively. The applicability of the method was validated by quantifying Ge in Ge-rich lignite, fly ashes (FA), and chlorinated distillation residue (CR) samples. The concentration of Ge in coals was 44.75–225.41 μg g−1, the content in FA was 0.68%–2.3 %, and the content in CR was 0.18 %, with the uncertainty of the method obtained being less than 0.5 %. X-ray fluorescence spectrometer (XRF) was used to verify the results. The difference between XRF data and ICP-OES data was less than 5 %, confirming the accuracy and reproductivity of the analytical method.

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.