Nitric Acid Salts Research Articles

Seeking forensic evidence of preparation routes to 2,4,6-trinitrophenol

ABSTRACT The explosive 2,4,6-trinitrophenol (picric acid) was prepared by five different methods using laboratory-grade chemicals as well as consumer-available chemicals in order to establish background forensic information. Nitrate sources were altered by using three concentrations of nitric acid or nitrate salts; an over-the-counter source of sulfuric acid was also investigated. Recovered products were identified using spectroscopic and thermal techniques. Impurities caused by over-the-counter starting materials were carried throughout the synthesis process to the crude recovered products and were detected by infrared and Raman spectroscopy and differential scanning calorimetry. In cases where nitrate salts were used; potassium picrate was recovered.

Quantitative detection of nitrates in green apples by ionometric method

The article discusses the importance of identifying nitric acid salts in fruits and vegetables, namely green apples, sold on the market. For determination, a potentiometric method with an ion-selective electrode ELIT-021 (nitrate) was used. As a result of the analysis, LOC was not exceeded in the samples, thus, they are fit for human consumption.

PM2.5 in Carlsbad Caverns National Park: Composition, sources, and visibility impacts

ABSTRACT Carlsbad Caverns National Park in southeastern New Mexico is adjacent to the Permian Basin, one of the most productive oil and gas regions in the country. The 2019 Carlsbad Caverns Air Quality Study (CarCavAQS) was designed to examine the influence of regional sources, including urban emissions, oil and gas development, wildfires, and soil dust on air quality in the park. Field measurements of aerosols, trace gases, and deposition were conducted from 25 July through 5 September 2019. Here, we focus on observations of fine particles and key trace gas precursors to understand the important contributing species and their sources and associated impacts on haze. Key gases measured included aerosol precursors, nitric acid and ammonia, and oil and gas tracer, methane. High-time resolution (6-min) PM2.5 mass ranged up to 31.8 µg m−3, with an average of 7.67 µg m−3. The main inorganic ion contributors were sulfate (avg 1.3 µg m−3), ammonium (0.30 µg m−3), calcium (Ca2+) (0.22 µg m−3), nitrate (0.16 µg m−3), and sodium (0.057 µg m−3). The WSOC concentration averaged 1.2 µg C m−3. Sharp spikes were observed in Ca2+, consistent with local dust generation and transport. Ion balance analysis and abundant nitric acid suggest PM2.5 nitrate often reflected reaction between nitric acid and sea salt, forming sodium nitrate, and between nitric acid and soil dust containing calcium carbonate, forming calcium nitrate. Sulfate and soil dust are the major contributors to modeled light extinction in the 24-hr average daily IMPROVE observations. Higher time resolution data revealed a maximum 1-hr extinction value of 90 Mm−1 (excluding coarse aerosol) and included periods of significant light extinction from BC as well as sulfate and soil dust. Residence time analysis indicated enrichment of sulfate, BC, and methane during periods of transport from the southeast, the direction of greatest abundance of oil and gas development. Implications: Rapid development of U.S. oil and gas resources raises concerns about potential impacts on air quality in National Parks. Measurements in Carlsbad Caverns National Park provide new insight into impacts of unconventional oil and gas development and other sources on visual air quality in the park. Major contributors to visibility impairment include sulfate, soil dust (often reacted with nitric acid), and black carbon. The worst periods of visibility and highest concentrations of many aerosol components were observed during transport from the southeast, a region of dense Permian Basin oil and gas development.

Extraction kinetics of nitric acid from the nitric acid-hydrochloric acid-potassium chloride solution by tributyl phosphate

The preparation of potassium nitrate from nitric acid and potassium chloride is considered a promising process. It is essential to efficiently separate nitric acid and hydrochloric acid from the crystallization mother liquor containing nitric acid, hydrochloric acid, and potassium salt. This article explored the thermodynamic equilibrium of nitric acid extracted from the nitric acid-hydrochloric acid–potassium chloride system by tributyl phosphate. It was discovered that nitric acid and tributyl phosphate are combined through TBP·HNO3. A constant interfacial area cell was adopted to investigate the extraction kinetics of nitric acid by tributyl phosphate dissolved in sulfonated kerosene. The most obvious finding to emerge from this study is that the extraction of nitric acid in this system occurs at the organic-aqueous interface. Which is jointly controlled by the diffusion of organic phase substances and interfacial chemical reactions. Finally, the mathematical model was established to reasonably describe the overall rate equation of nitric acid extraction, and the corresponding mass transfer coefficient and reaction rate constant were obtained.

Протонпроводящая керамика на основе гафната и церата бария, легированных оксидами циркония, иттрия и иттербия для электролитов топливных элементов

Nanopowders of the compositions BaHf1 – xYbxO3 – δ (x = 0.04; 0.08; 0.10) and BaCe0.9 – xZrxY0.1O3 – δ (x = 0; 0.5; 0.6; 0.7 and 0.8) were synthesized by the combined crystallization and nitric acid salts using the citrate-nitrate method. Those nanopowders were used to produce ceramic materials with a cubic crystal structure of the perovskite type, with a grain size of ~ 20 – 70 nm. The study of electrophysical properties revealed that they have a proton type of conductivity in the temperature range of 500 – 700 °C; σ = 10–2 – 10–5 Cm/cm. Type and mechanism of electrical conductivity of ceramics of the composition BaHf1 – xYbxO3 – δ (x = 0.04; 0.08; 0.10) have been studied both experimentally and using theoretical calculations-by computer modeling using the electron density functional method; the results are in good agreement. The research shows the prospects of using the obtained ceramic materials as proton-conducting electrolytes of solid-oxide fuel cells.

Structural and spectroscopic insights on the coordination chemistry of the rigid heterotopic chelating ligand 1H-pyrazolo[4,3-h]quinoline

In this work, we report the coordination chemistry of a rigid heterotopic ligand 1H-pyrazolo[4,3-h]quinoline HL1 in copper(II) and zinc(II) complexes and examine both the structural properties and solution-phase behavior of these species. On reaction with zinc(II) nitrate in acetonitrile, a mononuclear complex [Zn(HL1)2(OH2)2](NO3)2 1 is generated, where a size mismatch between the metal ion and the binding pocket leads to an anomalously long Zn–N bond to the pyrazole nitrogen. This is consistent with solution-state absorption and fluorescence measurements which indicate a relatively low stability constant logβ of 9.1(3) in acetonitrile. The reaction of HL1 with copper(II) nitrate in methanol gave four new crystalline phases, the major forms of which are two polymorphs of [Cu2(μ2-L1)2(NO3)2(MeOH)2] 2α and 2β which also constitutes the dominant solution-phase behavior of this mixture. Additionally, trace amounts of the nitric acid salt of HL1 were crystallized along with the slow formation of a tetranuclear species [Cu4(μ2-L1)6(OH2)2](NO3)2 · 2MeOH 3 which also features anomalously long bridging distances from L1 as a result of its backbone rigidity.

Utilization of coffee pulp waste for rapid recovery of pectin and polyphenols for sustainable material recycle

Coffee pulp is one of the major underutilized byproduct of coffee processing in farm level. Disposal of this agro-industrial waste has become one of the most challenging tasks for coffee planters. However, most of the efforts are towards the management of coffee pulp as an effluent, and not-on re-use. The problem is compounded due to the large volumes produced in diluted forms, which makes it expensive to reuse. The preliminary proximate analysis of coffee pulp indicated it to be rich in pectin and polyphenols. The efficacy of various chemicals like ethanol, sulfuric acid, hydrochloric acid, nitric acid, ammonium oxalate and metal salts for effective precipitation of pectin from coffee pulp was evaluated. HPLC characterization of the extracted and concentrated polyphenols fractions was analyzed. The maximum extraction of pectin was achieved by using metal salts and ethanol with 6.0% and 6.7% on wet weight basis respectively. The equivalent weight of extracted pectin (1180.5 mg/g) was found to be higher than that of commercial pectin (724.8 mg/g). The methoxyl content of the commercial pectin and crude pectin were 9.3 and 5.6% respectively. Gallic, vanillin, catechin, ethyl catechol, coumaric, Caffeic, and ferulic acid were the major polyphenols as quantified by the HPLC. The polyphenol fraction showed a good antioxidant activity with phosphomolybdate, FRAP, DPPH, and ABTS radicals respectively. The sustainable utilization of coffee pulp as a source of pectin and polyphenols with good antioxidant activities could help to solve the problem of waste generated in coffee processing in farm level.

Features of recording the analytical signal of beryllium using APESI mass-spectrometry and different procedures of sample preparation

The significance of the problem of determining the concentration of beryllium in solutions is substantiated. A method of APESI mass-spectrometry (atmospheric pressure electrospray ionization with in-source atomization) is compared with a number of other common procedures used for solving the aforementioned problem and a number of advantages of APESI mass spectrometry are highlighted. The possibility of measuring the beryllium concentration in various chemical forms using APESI mass-spectrometry is studied. We used sulfate, nitric acid and chloride salts of beryllium. The measurements were carried out on a specialized small-sized mass spectrometer MI-20 «LowMass» developed at MS-Bio Company, Russia. A schematic diagram of the device designed to determine the concentration of beryllium in solutions is presented and described. A technique of solution preparation and measurement procedure are proposed. Presented ass spectra obtained on the samples containing beryllium and lithium isotopes were used as an internal standard. It is shown that beryllium can be detected from the salts of chloride and nitric acids with close relative sensitivity coefficients. The obtained detection limit for beryllium chloride in those measurements was ~1 – 2 × 10–8 M. At the same time, the analytical signal of beryllium cannot be detected during electrospray of the solution of beryllium sulfate under any experimental conditions. It has been suggested that this effect may be attributed to the features of dissolution of beryllium sulfate, in particular, to hydrolysis and formation of complex compounds with sulfate, including complex polymer and colloidal forms.

CONVERSION OF PROPANE-PROPYLENE FRACTION INTO AROMATIC HYDROCARBONS ON MODIFIED ZEOLITE CATALYSTS

The process of transformation of propane-propylene fraction into aromatic hydrocarbons on zeolitecontaining catalysts modified Zn, La, Cr, Zr and P was discovered. The process was carried out in an installation in aflow installation at atmospheric pressure with a temperature variation from 350 to 600°C and a volumetric feed rateof 150-1020 h-1. The catalysts were prepared by impregnation of aluminum hydroxide and zeolite ZSM-5 withaqueous solutions of nitric acid salts of metals and phosphoric acid. The physical and chemical characteristics of thedeveloped catalysts are studied. The BET method established that the surface of the developed catalysts fluctuateswithin 211.0-274.0 m2/ g of the catalyst. Catalysts are predominantly mesoporous: pores with d ≈ 2.0-3.0 nmpredominate.It is shown that the developed modified zeolite-containing catalysts have high catalytic activity and selectivityin the process of processing the propane-propylene fraction into aromatic hydrocarbons. The predominant productsformed during the processing of C2-C4 alkanes are toluene and benzene. It was found that the highest yield ofaromatic hydrocarbons is 52.8% (550°С, 150 h-1) on the catalyst Zn-La-Р-Cr-ZSM-Al2O3 with a conversion rate of100.0%, selectivity for aromatic compounds - 52.8%.Modified zeolite-containing catalysts have multifunctional properties. The composition of liquefied petroleumgas processing products shows that the formation of aromatic hydrocarbons occurs in one stage as a result ofcracking, dehydrogenation, oligomerization, dehydrocyclization, alkylation reactions

Approaches to a Mathematical Modeling of the Density of Nitrate Solutions on the Basis of Concepts of Apparent Molar Volume As Applied to Hydrometallurgical Processes of the Nuclear Fuel Cycle

A method is suggested for calculating the density of single-component aqueous solutions of nitric acid and nitrate salts contained in solutions used in hydrometallurgical processes on the nuclear fuel cycle. The method uses apparent molar volumes and the water concentration. The method makes it possible to calculate the density of nitric acid solutions up to 17 M (HNO3 dihydrate) and salts to the point of formation of saturated solutions with an error not exceeding 0.2%. The values of the apparent molar volumes linearly depend on the concentration of water, and the apparent molar values approximated to the infinite dilution correspond to the Pitzer values.

One-step method for obtaining bifunctional charcoal and study of its properties

Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust) impregnated with the mixture of phosphoric acid, urea and nitric acid salts has been developed. Active influence of impregnates on the process of carbonization and formation of carbon residue has been demonstrated. It is established that carbon residue obtained in the interval of heating 20–700 °С possesses high sorption activity to the vapors of organic compounds and has ion-exchange capacity. It has been shown that the value of carbon residue depending on the impregnate used in the wood increases by 3,1 times at 600 °С and by 4,2 times – at 700 °С as compared to the yield of non-treated initial raw materials.

MORPHOLOGICAL PECULIARITIES OF RAT BONE MARROW UNDER THE INFLUENCE OF NITRATE SALTS IN INCREASED CONCENTRATIONS

The study of the qualitative composition of water and food products revealed the increased concentration of nitrates in their composition. Nitric acid salts in toxic doses can lead to disorders of the endocrine system, blood circulation, central nervous system, etc. Bone marrow is one of the most sensitive organs, which is responsible for the formation of cellular elements of blood. The object of our research was to study the morphological peculiarities of the bone marrow of rats under the influence of nitrate salts on the body and to determine the regularities of subacute and chronic hemotoxic effect of xenobiotics on the process of granulocyto-, erythrocyto- and thrombocytopoiesis. The study was conducted on 48 mature male rats. Nitrate Na (NaNO3) was used as xenobiotic. The animals were removed from the experiment on 10th, 30th and 90th day. The qualitative and quantitative composition of the parenchymatous and stromal component of the bone marrow was studied on the samples, stained with hematoxylin and eosin. During the experiment, the most expressed changes were observed in erythron: reduced number of nuclear cells in erythroid islands, signs of their diserythropoiesis – focal vacuolization, abnormal shape and size of the nuclei, their fragmentation, pathological inclusions in cytoplasm. Changes in granulocytopoiesis were expressed by the disturbance of their stratification – precursors with different degree of maturity were present in all parts of the medullary canal. Changes in megakaryocytes were expressed by their focal accumulation in the form of clusters and partial dislocation, regarding the sinusoids. The observations on animals revealed the term-dependent nature of changes in the bone marrow. On the 90th day, a progression of qualitative and quantitative changes in hematopoietic tissue was determined. The hemotoxic effect was expressed by disorders in the maturation of all its precursors – the ratio of parenchyma-stroma was still reduced, dysplastic changes in erythron increased, focal dystrophic changes in the stromal component of the bone marrow were observed.

Study of impregnated cellulose thermal treatment process and properties of obtained active carbon

Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust), impregnated with the mixture of phosphoric acid, urea and nitric acid salts has been developed. Active influence of impregnates on the process of carbonization and formation of carbon residue has been formed. It is established that carbon residue obtained in the interval of heating 20°С–(500°С–700)°С, possesses high sorption activity to the vapors of organic compounds and has ion-exchange capacity. It has been showed that the value of carton residue depending on the impregnate used in the wood increases compared to the yield of non-treated initial raw materials by 3.1 times at 600°С and by 4.2 times at 700°С.

A novel topical agent in the treatment of seborrheic keratoses: A proof of concept study by clinical and dermoscopic evaluation.

In this proof of concept study, 50 lesions from 15 patients with multiple seborrheic keratoses (SKs) were treated with a novel aqueous solution containing nitric acid, zinc and copper salts, and organic acids (acetic, lactic, and oxalic acid). Treatment consisted in the application of an amount of the solution sufficient to obtain a whitening/yellowish reaction. Application of the nitric-zinc solution was performed every other week until clinical and dermoscopic clearance or crust formation, for a maximum of 4 applications. Efficacy evaluation was performed at 8 weeks (T1) and 6 months (T2). All subjects, who reported no or minimal discomfort during and after the application of the solution, completed the study. At T1, a complete clinical and dermoscopic resolution was observed in 37 lesions after an average of 3 applications/lesion (range 2-4). A partial response, with minimal persistent residual spots, was detected in the remaining 13 lesions. All patients with complete clearance showed no relapses at a 6-month follow-up (T2). The positive preliminary results indicate that this novel solution may represent a promising alternative option for SKs especially in patients not keen or eligible to undergo invasive tissue-destructive procedures.

Modeling Speciation and Solubility in Aqueous Systems Containing U(IV, VI), Np(IV, V, VI), Pu(III, IV, V, VI), Am(III), and Cm(III)

A comprehensive thermodynamic model, referred to as the Mixed-Solvent Electrolyte model, has been applied to calculate phase equilibria and chemical speciation in selected aqueous actinide systems. The solution chemistry of U(IV, VI), Np(IV, V, VI), Pu(III, IV, V, VI), Am(III), and Cm(III) has been analyzed to develop the parameters of the model. These parameters include the standard-state thermochemical properties of aqueous and solid actinide species as well as the ion interaction parameters that reflect the solution’s nonideality. The model reproduces the solubility behavior and accurately predicts the formation of competing solid phases as a function of pH (from 0 to 14 and higher), temperature (up to 573 K), partial pressure of CO2 (up to $$ p_{{{\text{CO}}_{2} }} $$ = 1 bar), and concentrations of acids (to 127 mol·kg−1), bases (to 18 mol·kg−1), carbonates (to 6 mol·kg−1) and other ionic components (i.e., Na+, Ca2+, Mg2+, OH−, Cl−, $$ {\text{ClO}}_{4}^{ - } $$ , and $$ {\text{NO}}_{3}^{ - } $$ ). Redox effects on solubility and speciation have been incorporated into the model, as exemplified by the reductive and oxidative dissolution of Np(VI) and Pu(IV) solids, respectively. Thus, the model can be used to elucidate the phase and chemical equilibria for radionuclides in natural aquatic systems or in nuclear waste repository environments as a function of environmental conditions. Additionally, the model has been applied to systems relevant to nuclear fuel processing, in which nitric acid and nitrate salts of plutonium and uranium are present at high concentrations. The model reproduces speciation and solubility in the U(VI) + HNO3 + H2O and Pu(IV, VI) + HNO3 + H2O systems up to very high nitric acid concentrations ( $$ x_{{{\text{HNO}}_{3} }} \approx 0.70 $$ ). Furthermore, the similarities and differences in the solubility behavior of the actinides have been analyzed in terms of aqueous speciation.

Importance of coarse‐mode nitrate produced via sea salt as atmospheric input to East Asian oceans

AbstractThe atmospheric input of anthropogenic total reactive oxygenated nitrogen (NOy) to ocean regions in East Asia during 2002–2004 was revisited with an updated regional chemical transport model and the latest emissions inventory. The updated model treats both fine‐ and coarse‐mode nitrate (NO3−). Coarse‐mode NO3− is produced by the reaction of nitric acid (HNO3) and sea salt particles. The modeling system reproduced the atmospheric concentration and wet deposition amount of NO3− quantitatively compared with observations. The fraction of coarse‐mode NO3− was also well captured. NOy deposition amounts over marginal seas and open oceans were 733 and 730 Gg N/yr, which are increases of 1.6‐ and 2.2‐fold, respectively, by including coarse‐mode NO3−. Anthropogenic NOx emissions from China were 5377 Gg N/yr, and 3060 Gg N/yr was exported from China; therefore, the NOy deposition amount over ocean regions in East Asia (1463 Gg N/yr) corresponded to almost half (48%) of the export amounts.

Extraction of uranium nitrate by novel unsymmetrical N,N’-dimethyl-N,N’-didodecyl diglycolamide

One novel unsymmetrical bisamide extractant, N,N’-dimethyl-N,N’-didodecyl diglycolamide (DMDDDGA), with different alkyl substituents attached to amidic N atom was synthesized and used to evaluate its extraction capability of uranium nitrate. The extraction behavior of uranium nitrate in nitric acid was studied with 0.10 mol dm−3 DMDDDGA/kerosene. DMDDDGA exhibits high extraction ability for uranium nitrate due to its methyl, the smallest alkyl, which results in lower steric hindrance in the complexation with uranium ion. The stoichiometry of DMDDDGA-U(VI) was determined by linear regression analysis of extraction data. The effect of the concentration of nitric acid and nitrate salt, and the temperature on the extraction was investigated.

Oxygen and nitrogen isotopic composition of nitrate in commercial fertilizers, nitric acid, and reagent salts

Nitrate is a key component of synthetic fertilizers that can be beneficial to crop production in agro-ecosystems, but can also cause damage to natural ecosystems if it is exported in large amounts. Stable isotopes, both oxygen and nitrogen, have been used to trace the sources and fate of nitrate in various ecosystems. However, the oxygen isotope composition of synthetic and organic nitrates is poorly constrained. Here, we present a study on the N and O isotope composition of nitrate-based fertilizers. The δ15N values of synthetic and natural nitrates were 0 ± 2 ‰ similar to the air N2 from which they are derived. The δ18O values of synthetic nitrates were 23 ± 3 ‰, similar to air O2, and natural nitrate fertilizer δ18O values (55 ± 5 ‰) were similar to those observed in atmospheric nitrate. The Δ17O values of synthetic fertilizer nitrate were approximately zero following a mass-dependent isotope relationship, while natural nitrate fertilizers had Δ17O values of 18 ± 2 ‰ similar to nitrate produced photochemically in the atmosphere. These narrow ranges of values can be used to assess the amount of nitrate arising from fertilizers in mixed systems where more than one nitrate source exists (soil, rivers, and lakes) using simple isotope mixing models.

Experimental Comparison of 2-methylimidazole Nitration by Nitric Acid and Nitrate Salts of Alkali Metals

The processes of nitration of 2-methylimidazole to produce 2-methyl-4(5)-nitroimidazole are considered in this paper. The processes of nitration by mixture of nitric and sulfuric acids and nitrate salts of alkali metals were compared. It was found the nitration of nitrate salts of alkali metal proceeds smoother. The yield of the desired product 2-methyl-4(5)-nitroimidazole was 85 % and 95% in case of nitric acid and nitrate salt.

Assessment of the efficacy of a new formulation for plantar wart mummification: new experimental design and human papillomavirus identification

Cutaneous warts are caused by infection of the epidermis with human papillomavirus (HPV). Cryotherapy using liquid nitrogen is one of the most common local treatments. In this study, we used a novel ex vivo approach to compare the efficacy of a new product with conventional liquid-nitrogen cryotherapy by studying epidermal histology and assessing the presence of HPV types 1 and 2 DNA in plantar warts. The studied formulation, which acts by tissues mummification, is a combination of nitric acid, organic acids and metallic salts. We found that, similar to liquid nitrogen, the studied product induced alterations in the wart structure. In addition, unlike liquid nitrogen, this product also reduced the amount of HPV DNA. The results suggest that there is a poor correlation between the histological response and the antiviral efficacy of standard wart treatment.