Mixture Of Nitric Acid Research Articles

Evaluation of selected minerals and health risk and proximate analysis of wasawasa (a street food)

This study was carried out to determine the proximate composition and the potential heavy metal health risk that may be associated with the consumption of wasawasa, a dish made from locally milled yam peels, by examining the presence of six metals (iron, nickel, chromium, sodium, and magnesium and potassium) in samples procured. Sixteen (16) samples of ready-to-eat wasawasa were collected from Aboabo, Manhyia, Sawaba, Asawase, Adenyase, and Ayigya in Kumasi, since these are the communities where wasawasa is mainly produced, sold, and consumed. The samples were digested with a nitric, perchloric, and sulfuric acid mixture and analyzed using a microwave plasma atomic emission spectrometer (Agilent 4210 MP-AES). The average concentrations of metals were Na (8506.88 mg/kg), Mg (222.63 mg/kg), Fe (84.45 mg/kg), Cr (2.31 mg/kg), K (1702.08 mg/kg, and Ni (1.12 mg/kg). Proximate analysis was used to determine Protein, fat, ash, moisture, and fiber content of the local wasawasa, which were found to be 15.667 %, 0.45 %, 1.00 %, 27.54 %, and 0.41 %, respectively. The hazard index of the heavy metals (Fe, Ni and Cr) for both adults and children were each greater than one, indicating the population is likely to experience non-carcinogenic effects from the consumption of wasawasa.

Effects of chemical etching on surface structure and tribological behavior of silicate substrates

Abstract This study investigated the effect of chemical etching on the surface structure and tribological behavior of silicate substrates. Silicate surfaces were etched using a mixture of nitric acid (HNO3) and ammonium bifluoride (NH4HF2) for durations ranging from 1 to 60 min. The etched surfaces were characterized using optical microscopy, scanning electron microscopy, surface profilometry, water contact angle measurements, and UV–vis spectroscopy to evaluate the changes in surface morphology, roughness, wettability, and optical properties. Tribological performance was assessed using reciprocating ball-on-plate friction tests. The results showed that increasing the etching time resulted in the formation of microscale surface features, increased surface roughness, enhanced hydrophilicity, and reduced optical transmittance. The average friction coefficient decreased with an increase in the etching time up to 30 min, beyond which a slight increase was observed. The 1-minute etched specimen exhibited the best wear resistance with the narrowest wear track and the least material removal. The improved tribological performance was attributed to the formation of a stable transfer film, reduced real contact area, and entrapment of wear debris. This study highlights the potential of chemical etching as a technique to tailor the surface structure and tribological properties of silicate materials for various applications.

Phase analysis of near equiatomic bulk FeRh alloys: X-ray versus neutron diffraction and magnetization measurements

The information obtained by X-ray diffraction (XRD) by impinging the X-ray beam onto the flat surface of bulk Fe–Rh alloys is contrasted with that provided by the thermomagnetic analysis curves measured under a magnetic field of 5 mT and 2 T, and the neutron diffraction (ND) patterns. The experiments were performed on slices cut from bulk Fe50Rh50 and Fe49Rh51 alloys prepared by induction melting followed by 48 h of thermal annealing at 1273 K. Whereas ND patterns and magnetization curves, directly and indirectly point out that the samples are single-phase with a CsCl-type crystal structure undergoing a magnetoelastic transition that changes the magnetic structure from antiferromagnetic to ferromagnetic on heating, multiple phases are identified in the XRD patterns, which modify upon polishing or etching the surface with a mixture of hydrochloric (HCl) and nitric acid (HNO3) at a volume ratio of 90:10 from 30 to 210 min. The limitation of XRD for accurately characterizing the phase constitution within the bulk of Fe–Rh alloys is underlined.

Preparation of a colorimetric hydrogel indicator reinforced with modified aramid nanofiber employing natural anthocyanin to monitor shrimp freshness.

The pH-responsive hydrogels have potential applications in food visualization detection, but their fragile mechanical properties limit their applicability. The excellent mechanical properties and thermal stability of aramid nanofibers (ANFs) can improve the structural stability of hydrogels. In this study, the surface properties of ANFs were enhanced through modification to improve their surface activity. The modified ANFs, designated as ANF-SN, were produced following treatment with a mixture of sulfuric acid (H2SO4) and nitric acid (HNO3), which led to increased reactivity and dispersibility of the ANFs due to the proliferation of active groups on their nanofiber surface. The preferred anthocyanin extract from purple sweet potatoes (purple sweet potato extract [PSPE]) had significant color responses to pH (2-12) and ammonia vapor. A stable dual-network colorimetric hydrogel was fabricated by combining ANF-SN, polyvinyl alcohol/sodium alginate (PVA/SA), and PSPE through a two-step method (freeze-thawing and staining). Characterization analysis showed that the strong acid modification of ANFs effectively improved their chemical reactivity. ANF-SN was better than ANF in promoting the formation of hydrogen bond networks, enhancing hydrogel network structures, and improving the viscoelasticity of hydrogels. The optimal hydrogel indicator PVA/SA/ANF-SN/PSPE had good color responsiveness and sensitivity to ammonia. It can also be used to further determine shrimp freshness value using a smartphone and RGB color-picking software.

Effect of graphite oxide on the mechanical, thermal, structural and hydrophilicity proprieties of Polypropylene / Poly(Propylene-Glycol) Acrylate / Glycidyl Methacrylate PP/PPGA/GMA composite

This research aims to investigate the synergistic effects of grafting flexible fractions and incorporating reinforcing fillers in polypropylene (PP) matrix. The primary objective is to establish an experimental methodology for preparing and characterizing Polypropylene / Poly(Propylene-Glycol) Acrylate / Glycidyl Methacrylate (PP/PPGA/GMA) composites loaded with graphite oxide (GtO).The process of oxidizing natural graphite powder using a mixture of sulfuric acid and nitric acid was validated through various analytical techniques including IRTF, AFM, DRX, XRF and ATG. The grafting reaction of PPGA and GMA on polypropylene and the incorporation of graphite oxide with varying levels were carried out in the melt state in a Brabender internal mixer; Dicumyl peroxide (DCP) was used as a radical initiator. A comprehensive assessment of the obtained materials was conducted through conventional analyses encompassing mechanical properties (tensile and impact), thermal behaviors (ATG and DSC), morphological characteristics (SEM) and the chemical state of film surfaces (Contact angle).The investigation revealed two key outcomes. Firstly, it showcased the grafting effect of PP on the polymer's morphology and properties. Secondly, it underscored the consequential impact of incorporating graphite oxide on the overall behavior of produced materials.

Surface‐modified graphite based polymer nanocomposites for high‐temperature geothermal applications

AbstractThis research aims to develop novel economical and thermally‐stable polymer nanocomposites to seal geothermal wells by dispersing surface‐modified graphite into an inexpensive raw polymer. Using a mixture of nitric acid and sulfuric acid, a nano‐scale graphite filler, namely small‐size lamellar graphite (SFG15), was surface‐modified, which introduced considerable oxygen and carboxylic (COOH) groups to graphite surfaces, as verified by X‐ray photoelectron spectroscopy (XPS) analysis. Polymer nanocomposites were fabricated by dispersing different concentrations of modified graphite SFG15, including 1.5, 3, 6, and 9 wt%, into the ethylene propylene diene monomer (EPDM) matrix. First, characterization techniques, including wide‐angle X‐ray scattering (WAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), were employed to examine modified graphite dispersion in the nanocomposites. Then, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) were used to quantitatively study the key mechanical and thermal properties of the nanocomposites. It was found that introducing modified SFG15 to EPDM enhances its resistance to deformation at high temperatures significantly. Notably, 9 wt% of modified SFG15 showed superior performances in improving the storage modulus of EPDM by 191.17%, enhancing loss modulus by as high as 136.08%, and decreasing tan by 18.93%. After introducing modified graphite, the energy needed for melting EPDM was increased markedly, which was accompanied by improvement in its heat capacity. Compared with pure EPDM, the onset temperature of degradation for developed nanocomposites could be increased by over , and the temperature of 50% degradation was raised by up to . Possessing the improved mechanical and thermal performances, the nanocomposites developed could be a primary choice for materials used to seal geothermal wells.Highlights A technique is developed to reinforce low‐cost polymers for high‐temperature use. Reinforcement of EPDM with high concentrations of modified graphite is investigated. Modified graphite increases the high‐temperature storage modulus of EPDM by 191.17%. Degradation temperatures of EPDM are enhanced by modified graphite considerably. Low‐cost polymer composites are essential seals for application in deep geothermal wells.

Insights into the hierarchical geometries of hybrid low-dimensional carbons

Hybrid 3D nanomaterials have been prepared by immobilizing the acid-functionalized MWCNTs into the edge-functionalized/oxidized Few Layer Graphene (FLG) flakes to address the dispersion and exfoliation of FLG flakes. Both acid-functionalized MWCNTs and the edge-oxidized FLG flakes were prepared in the laboratory. The acid-functionalized MWCNTs were prepared via oxidative treatment using a mixture of nitric acid (HNO3) and sulphuric acid (H2SO4). Fenton’s reaction was utilized for the preparation of the edge-oxidized FLG flakes using graphite flakes as the starting material. After the functionalization, the presence of the oxygen-containing functional groups was confirmed using FTIR spectroscopy and XPS spectroscopy. The thermal stabilities of the nanomaterials were compared using TGA thermogram and the 3D nanomaterial was observed to be more stable than any other nanoparticles that were prepared and reported in this paper. The surface morphology was observed using the SEM and TEM, and the immobilized functionalized MWCNTs between the edge functionalized FLG flakes were observed. The XRD spectra of the nanoparticles were also compared and Raman analyses have been carried out.

ХІМІЧНА СТІЙКІСТЬ І СТАБІЛІЗАЦІЯ НІТРАТУ КРОХМАЛЮ

It was studied the Processes of ensuring chemical stability (stabilization) of starch nitrate obtained by nitration of starch by two ways: nitric acid and nitric-sulfuric acid mixture. It has been confirmed that, in the first case, starch nitrate has much higher stability due to the absence of low-stable sulfuric acid esters. It is shown that to ensure it in this case, 10 minutes of washing of starch nitrate in 0.19 m3/kg of hot water (95 °С) is sufficient. It was established that in the case of nitration with nitric acid, an increase in the nitrogen content in starch nitrate, which characterizes the amount of nitroester bonds in it, leads to a decrease of the temperature atthe beginning of active decomposition, whichapproaches 168 °C for the maximum nitrogen content (14.14 %). This temperature is proposed as an indicator for evaluation of starch nitrate chemical resistance.The obtained data are necessary for the development of starch nitrate production technology.

N-Guanylurea dinitramide: Optimal synthesis process, basic properties and spectroscopic data

N-Guanylurea dinitramide (GUDN), also known as FOX-12, is indeed a fascinating organic dinitramide salt with high insensitivity and good thermal stability. It shows great promise for use in next-generation insensitive munitions. In this study, GUDN was synthesized through the nitration reaction of ammonium sulfamate salt with an acid mixture (HNO3/H2SO4) and guanylurea salts in water. The optimal conditions for this synthesis have been determined, including reaction temperature at -40 oC, the nitration reaction time of 45 minutes, and specific molar ratios of the components, which include guanylurea sulfate, ammonium sulfamate, and the mixture of sulfuric and nitric acid. Additionally, various properties and spectral data of GUDN, such as FTIR, 1H-NMR, 13C-NMR, DSC-TG, XRD, and UV-Vis, have been thoroughly studied in the referenced article.

Determination of Heavy Metals in the Hair of Some Occupational Workers in Some Local Government of Adamawa State, Nigeria

This study was conducted to determine the heavy metals concentration in hair samples of occupational workers (mechanics, electricians, and welders) in the Mubi, Gombi, and Numan local government areas of Adamawa State. The hair sample was washed with non-ionic detergent and acetone to remove contamination and digested with 20cm3 of 3:1 mixture of concentrated nitric acid and perchloric acid. The sample was later analysed using Atomic Absorption Spectrometry for the determination of heavy metals lead (Pb), cadmium (Cd), nickel (Ni), cobalt (Co), Zinc (Zn), chromium (Cr), manganese (Mn) and copper (Cu). The results of this study show that heavy metals in hair samples from different subjects accumulate differently based on exposure. The concentrations of heavy metals in welder workers' hair are the highest values among other occupations (mechanics and electricians), except in Mubi where mechanics workers have the highest concentration. The levels of all the metals increase with respect to age except age 26 – 40 in Mubi which is even higher than the aged group 41 – 55. This research shows that there is a statistically significant relationship between the type of work or workplace and the heavy metal concentration detected in hair samples. There is an instantaneous need for public awareness about the hazards of this occupation to enable occupational workers to take necessary precautionary measures. Keywords: Heavy metals, Human hair, Occupational workers (welders, mechanics, and electricians)

Assessment of essential and potentially toxic metals in raw cow milk from Mukaturi town, Oromia Regional State, Ethiopia

Cow milk is a complete and highly nutritious source of food for humans. However, the quality of milk products has become a significant health concern for consumers, particularly infants and children, in many developing nations, including Ethiopia. The objective of this study was to determine the heavy metal levels in raw cow milk collected from dairy producers and collection centers in Mukaturi town, Ethiopia. Sixty raw cow milk samples (40.0 milk samples from dairy farms and 20.0 milk samples from collection centers) were randomly collected and digested using a mixture of nitric acid (HNO3), hydrogen peroxide (H2O2) and perchloric acid (HClO4) on a hot plate. The amounts of heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the milk samples were determined using inductively coupled plasma atomic emission spectroscopy (ICP–OES). The findings showed that the average concentrations of Pb (2.31 ± 0.127), Fe (0.566 ± 0.130), Ni (0.210 ± 0.0189), Cd (0.0372 ± 0.0230), Cr (0.369 ± 0.0162), and Co (0.225 ± 0.0150) in mgL−1 were higher than the allowable limits. This could pose a health risk to the public. However, the concentrations of Mn (0.044 ± 0.0369), Cu (0.195 ± 0.0450) and Zn (2.90 ± 0.0570) in mg L−1 were lower than or within the recommended limits and cannot pose any threat to consumers. The validity of the digestion processes was checked by the recovery test. The percentage recoveries of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were found to be in the range of 80.7–122 %, which is within the acceptable range. Therefore, special attention should be given to the continuous monitoring of heavy metal levels in raw milk among dairy producers and collection centers to minimize economic losses and the risk to consumer safety.

Evaluation of urinary trace element levels in patients with opioid use disorder undergoing methadone treatment in western Iran

The monitoring of essential and toxic elements in patients with Opioid Use Disorder (OUD) undergoing methadone treatment (MT) is important, and there is limited previous research on the urinary levels of these elements in MT patients. Therefore, the present study aimed to analyze certain elements in the context of methadone treatment compared to a healthy group. In this study, patients with opioid use disorder undergoing MT (n = 67) were compared with a healthy group of companions (n = 62) in terms of urinary concentrations of some essential elements (selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), calcium (Ca)) and toxic elements (lead (Pb), cadmium (Cd), arsenic (As), and chromium (Cr)). Urine samples were prepared using the acid digestion method with a mixture of nitric acid and perchloric acid and assessed using the ICP-MS method. Our results showed that the two groups had no significant differences in terms of gender, education level, occupation, and smoking status. Urinary concentrations of Se, Cu, and Fe levels were significantly lower in the MT group compared to the healthy subjects. However, the concentrations of Pb, Cd, As, Mn, Cr, and Ca in the MT group were higher than in the healthy group (p < 0.05). No significant difference was established between the levels of Zn in the two groups (p = 0.232). The results of regression analysis revealed that the differences between the concentration levels of all metals (except Zn) between two groups were still remained significant after adjusting for all variables (p < 0.05). The data obtained in the current study showed lower urinary concentrations of some essential elements and higher levels of some toxic elements in the MT group compared to the healthy subjects. These findings should be incorporated into harm-reduction interventions.

Cleaning of tungsten tips for subsequent use as cold field emitters or STM probes

Abstract This study investigates the crucial process of cleaning cold field emission electron emitters and scanning tunnel microscopy (STM) probes, particularly focusing on tungsten tips. The cleanliness of these tips is essential for maintaining optimal cathode properties, preventing impurities that can significantly affect the emission process. Various cleaning methods, including macroetching, ammonia cleaning, and hydrofluoric acid (HF) cleaning were explored and compared by scanning electron microscopy. The macroetching method, involving a mixture of hydrochloric acid, nitric acid, and hydrogen fluoride, proved to be too reactive, causing significant material removal and altering the tip’s structure. Ammonia cleaning did not significantly improve or harm the samples. However, oxide islands appeared in some areas, suggesting the potential formation of ammonium tungsten oxide. HF cleaning, specifically at 20% and 50% concentrations, demonstrated effectiveness in removing tungsten oxides without damaging the tip. Pre-cleaning with water and ethanol proved beneficial for subsequent HF refinement. Results suggest that HF is the most suitable method for oxide removal but a rinse with water is essential for removing residual sodium hydroxide. To maintain optimal properties, it is crucial to apply a less reactive layer quickly or transfer the tips to a water/ethanol bath to prevent oxidation.

Assessment of the health risk of some heavy metals in cabbage grown on dumpsite at Hanwa in Zaria, Kaduna State, Nigeria

Pollution of soil with heavy metals can lead to high concentration of the metals in plants, consequently in animals and human body. Cadmium, Copper and Lead concentrations were determined in soil samples and cabbage (Brassica oleracea) grown on a dumpsite at Hanwa in Zaria, Nigeria. Both the soil and plant samples were digested using a mixture of Nitric acid and Perchloric acid (ratio 3:1). The metals concentrations in the samples were determined using Atomic Absorption Spectroscopy (AAS). Soil parameters like Particle Size, pH, Moisture Content, and Organic Matter were also evaluated using standard methods. The results indicated much higher concentrations of heavy metals in the soil than roots, stems and leaves of the analyzed cabbage sample. The Cd level in the plant samples ranged from 1.20 to 1.70mg/kg (site) and 0.80 to 1.00mg/kg (control). Concentration of Cu in the samples ranged from 15.50 to 35.90mg/kg (site) and 7.30 to 13.90mg/kg (control) and Pb: 19.40 to 42.70mg/kg (site) and 5.80 to 26.40mg/kg (control)were above the recommended limit by joint FAO/WHO. The Transfer Factor (TF) of the studied metals from soil to cabbage leaves were in the order of Cd (0.92) &gt; Pb (0.58) &gt; Cu (0.44).In this study, the Health Risk Index (HRI) for Pb (3.421) was found to be greater than 1, which indicates significant potential health risks. The high level of these heavy metals places the consumers of cabbages grown within the dumpsite area at health risk. Cultivation of vegetables on metal dumpsites should be discouraged as the soils are polluted with heavy metals.

Comparison between Microwave Digestion and Conventional Open Digestion Method for Heavy Metals determination

In the present study a comparison between microwave assisted digestion and conventional wet acid open digestion system for dissolution of bivalve tissue samples was carried out. Sample matrix decomposition was done by using a mixture of concentrated nitric acid and hydrogen peroxide. The determination of trace elements (Zn, Co, Cu, Cd and Pb) in commercially popular bivalve species from two important fish landing centers in Mumbai was used for this purpose. The recovery of heavy metals after analysis was done using certified reference material TORT 2- Lobster hepatopancreas for both the digestion methods. The results of the present study indicate that microwave digestion system for heavy metal analysis is the preferred method for rapid and good quality results. It provides better recovery and precision for heavy metal analysis. The sample preparation step is much easier by microwave digestion system compared to conventional open digestion methods for heavy metal analysis. It is particularly ideal for trace metals like lead and cadmium as they are generally present in very small concentration in biological samples. In the current study microwave digestion proved to be better method than conventional open digestion method with rapid sample digestion process and least sample contamination problem.

Hydrofluoric acid-free etched MAX on 3D-printed nanocarbon electrode for photoelectrochemical hydrogen production

MXenes have emerged as a promising material for a disparate range of photo-electrochemical conversion and energy storage devices. However, most reported synthesis process involves hydrofluoric acid (HF) and fluoride-based compounds. HF severe toxicity persists impediment to the scalable production and fabrication of MXenes. Thus, fluoride-free protocols are currently being explored. Here, we demonstrate a novel fluoride-free protocol for the etching of the MAX phase (Ti3AlC2) utilizing an acidic mixture of nitric acid, phosphoric acid, and acetic acid. Such acidic etching modulated the electronic structure and chemical composition of the MAX surface converting it into MAX-derived flower-like titanium phosphate and titanium oxide which boosts its photo-electrochemical properties. The photo-electrochemical hydrogen evolution reaction is evaluated using 3D-printed and screen-printed carbon electrodes exposing under visible light illumination with 365 and 460 nm wavelengths. Such HF-free etched Ti3AlC2 MAX and the MAX-derived flower-like titanium phosphate and titanium oxide coated 3D-printed nanocarbon and screen-printed carbon electrodes demonstrate a novel process to be applied for an energy conversion application. This work will pave the way to etch other MAX phases through an environment-friendly and easy-handling technique that is to be used beyond photo-electrochemical applications.

Nitric Acid and Organic Acid Mixture Show Less Deviation in Extractability of Potassium Between Field-Moist and Air-Dried Soil

ABSTRACT Air-drying of soils for testing can cause fixation/release of potassium (K), showing a K status different from that of the field. We compared different extractants to find one with the least deviation in K-extractability between field-moist and air-dried soils. We chose two treatments (No-K and 150% of recommended K fertilization) of a field experiment (maize-wheat) for the study. Field-moist soil (0–15 cm) was collected at 3, 4, 5, 6, 7, 8, 23, 24, 25, and 26 days after the irrigation (DAI) from each replicated plot at the flowering stage of the 2018–19 wheat crop. Soil K, before and after air-drying, was extracted with 1 M ammonium acetate (NH4OAc), 0.1 M nitric acid (HNO3), 0.01 M calcium chloride (CaCl2), and 0.01 M organic acid mixture (OAM, mixture of 0.0025 M each of citric acid, malic acid, tartaric acid, and oxalic acid). Air-drying significantly (P < .05) affected the soil K for all methods except HNO3 in plots without K fertilization. However, air-drying’s effect on K release was more pronounced in No-K soils with high initial moisture content (>10%). Averaged over K-fertilization and initial soil moisture, the K-extractability using HNO3 and OAM showed the least deviation (9.6% for both) by air-drying. It was significantly (P < .05) lower than NH4OAc or CaCl2, which showed as high as 21.1–23.0% deviation due to air-drying. Hence, one should use 0.1 M HNO3 or 0.01 M OAM instead of 1 M NH4OAc to get an available K status closer to that in the field.

Effect of surface topography and wettability on shear bond strength of Y-TZP ceramic

Zirconia ceramics have been widely used as dental restorations due to their esthetic appearance and high flexural strength. The bonding of zirconia with resin cement should rely on both mechanical and chemical bonds. This study was performed to investigate the effect of zirconia surface topography and its wettability after surface pretreatments on the microshear bond strength (μSBS) of a resin cement. Zirconia slabs were prepared and randomly divided into 5 groups based on the surface treatment as follows: no treatment (control), air abrasion (AB), etching with hydrofluoric acid (F), the mixture of hydrofluoric acid and nitric acid (FN), or the mixture of hydrochloric acid and nitric acid (CN) for 10 min. The specimens were subjected to investigation of surface roughness characteristics [average roughness (Ra), peak-to-valley average distance (Rpv), skewness (Rsk), and kurtosis (Rku)] using atomic force microscopy (AFM) and measurements of surface contact angle (θc) and μSBS of a resin cement. In addition, the area % of the nanoscale surface irregularity (nSI%) was calculated from the AFM images. The effects of nSI%, Ra and θc on the μSBS were analyzed by multiple linear regression analysis (p < 0.05). Multiple regression analysis revealed that the nSI% was the most predominant factor for the μSBS (p < 0.001). A surface with larger nSI%, higher Ra and relatively lower θc was essential for establishing a reliable resin-zirconia bond.

Formation of N–O–H bearing species in HNO3 and H2O icy samples by heavy-ion irradiation: an infrared spectroscopic study

This article investigates the radiolysis of a mixture of nitric acid with water (HNO3:H2O) at 16 K in high-vacuum (residual pressure < 10−6 mbar). A nitric acid-water ice film was exposed to 40 MeV 58Ni11+ ion beam in a heavy ion accelerator facility in France. For this astrochemically- and atmospherically-relevant ice mixture of nitric acid and water, we analyze the possible formation and destruction processes of N–O bearing species, thus providing spectroscopic data in the infrared (IR) region for theoretical, laboratory and observational future studies. The irradiation synthetized 18 species which were posteriorly examined by infrared spectroscopy: N2O, NH3, NO, NO2 and H x N y O z molecules, such as hidroxylamine (NH2OH), nitrous acid (HONO) as well as other species with bonding N–O, N–H and H–O–N converting surface-adsorbed nitrogen oxides into astrochemically active NO x . The interaction of HNO3 and H2O originates H–N–O molecular complexes, which were investigated as particular cases of the hydrogen-bonded species formed by a more electronegative atom (N or O) interacts intra or intermolecularly with a donor atom (N or O) and observed in the interstellar medium with higher quantities or great abundances. The HNO3 and H2O destruction cross sections have been determined to be 8.5 × 10−13 and 1.2 × 10−13 cm2, respectively, for the mentioned experimental conditions.

The Identity and Mineral Composition of Natural, Plant-Derived and Artificial Sweeteners.

The qualitative X-ray phase analysis of natural and artificial food sweeteners was applied to trace the authenticity of such food additives. The mineral composition of different sweeteners commonly added to foods was studied to estimate their mineral profiles and assess the risk related to the toxic elements intake caused by sweetener consumption. The concentration of twenty elements (Ag, Al, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sr, Ti, V, and Zn) was measured using the inductively coupled plasma-optical emission spectroscopy (ICP-OES) method after the representative samples were wet-digested with a concentrated nitric acid and hydrogen peroxide mixture in a closed-vessel microwave-assisted system. Differences between the mineral compositions of the examined sweeteners were statistically evaluated and discussed. The relationships between the concentrations of the elements determined in the analyzed sweeteners were also investigated. The successful application of the X-ray powder diffraction method proved the identity of all investigated sweeteners; all the analyzed products contained the expected sweetening agent. The results of the quantification of all the elements in the examined sweeteners indicated that these products cannot be considered nutritionally dense. Hence, the presence of toxic elements like Cd, Cr, Ni, and Pb distinctly indicates the need to test such products to guarantee their quality and ensure consumer safety.