Nitrite Research Articles

Therapeutic potency of kaempferol against Naja haje venom induced neurotoxicity, inflammation, biological activities, and antioxidant system damage: a pre-clinical antivenom evaluation.

Naja haje envenoming manifests organ system disorders leading to severe fatalities due to the venom's toxins. The neutralizing capacity of kaempferol has been reported against some medically significant snake venoms with exception of N. haje venom (NhV). This current study assessed the neutralizing profile of kaempferol against toxicities induced by NhV using in vitro and in vivo methods. In in vitro, NhV induced wide spectrum of toxic biological activities with substantial increase in hemorrhagic, anticoagulating, and hemolytic effects. Likewise in the in vivo study, the venom caused hematological disorders by inducing acute anemia, thrombocytopenia, and leucopenia in envenomed rats. Also, the venom caused detrimental effect on the antioxidant defense system of the brain through significant (P < 0.05) elevation of malondialdehyde (MDA), nitrite (NIT), and suppression of reduce glutathione (GSH) antioxidant, superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) enzymes. Additionally, the levels of neurotoxicity biomarkers, monoamine oxidase (MAO) and acetylcholinesterase (AChE), and pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were significantly (P < 0.0.5) enhanced by NhV in the brain of envenomed rats. Severe pathohistological effects were observed in brain tissues of the envenomed rats. However, kaempferol substantially (P < 0.05) inhibited the NhV-induced biological activities, normalized the hematological disorders, enhanced antioxidants system functions, and significantly (P < 0.05) suppressed the levels of neurotoxicity biomarkers and pro-inflammatory cytokines. Severe structural alterations observed in the brain tissues were ameliorated after kaempferol treatment. Further exploration of kaempferol could lead to the development of an alternative therapy for treatment of N. haje envenoming.

Study on the effect of nano-silica on the early-age strength and microstructure of cement paste mixed with calcium nitrite under negative temperature conditions

During construction at low temperatures, fresh concrete is susceptible to early freeze damage, which can permanently damage the concrete structure. Therefore, this study aimed to enhance the early-age strength and durability properties of the cement paste at −5 ℃ by incorporating calcium nitrite (CN) antifreeze and nano-silica (NS). First, the effects of CN and NS on the fresh properties of the cement paste were measured by setting time and bleeding rate tests. Subsequently, the mechanical properties and chloride content after salt solution erosion were tested for each group of specimens, and the change in slurry densification was further observed by ultrasonic pulse velocity and resistivity tests. Finally, the hydration products and microstructure of the specimens were analyzed using XRD and SEM tests. The results showed that the addition of CN and NS could reduce the setting time of cement paste and avoid the bleeding phenomenon of cement paste under negative temperature environment. The decrease in curing temperature and the use of NS both inhibited the promotion of C3A hydration by nitrite ions, which led to a decrease in nitrite-AFm content. However, NS can compensate for the reduced nitrite-AFm content by promoting the production of hydrated C-S-H through nucleation and pozzolanic effects. Ultimately, the strength and resistance of the slurry to chloride erosion are improved.

Feasibility of controlled nitric oxide generation via ascorbate induced chemical reduction of nitrite ions.

Inhalable nitric oxide (iNO) is a lifesaving, FDA-approved drug to improve oxygenation in persistent pulmonary hypertension of the newborn. iNO also has many other applications in lung diseases owing to its vasodilatory and antimicrobial effects. However, its wider therapeutic application is often prohibited by the high cost and logistical barriers of traditional NO/N2 gas tanks. Development of low-cost, portable and tankless nitric oxide (NO) generators is a critical need to advance iNO therapy. Here, we describe the feasibility of NO generation by the controlled reduction of nitrite (NO2-) ions. This was accomplished by using ascorbate to reduce NO2- ions mediated by a copper(I/II) redox pair complexed by an azo-crown ether ligand ([Cu(II)L]2+/[Cu(I)L]+) in the solution phase. We found that oxalate, a decomposition product of ascorbate, interferes with the NO generation from the copper-ligand complex. This interference was mitigated, and the reaction was further optimized. NO generation through this method was found to be highly controllable via its proportionality to the flow rate of NO2- injected into a reaction chamber containing the reducing components. Hence, this simple approach adds to the current collection of innovative methods under development to obviate the use of NO tanks for iNO delivery.

Portable Mini-Electrochemical Cell: Integrating Microsampling and Micro-Electroanalysis for Multipurpose On-Site Nitrite Sensing.

In modern analytical chemistry, one of the primary goals is to develop miniaturized, easy-to-use sensing tools, particularly those with multitasking capabilities. In this work, we designed a mini-voltammetric cell that integrates a modified Au microelectrode (Au/Au NPs as the working electrode) and an Ag/AgCl reference electrode installed within a micropipette tip. This combined tool not only enables portable and on-site microvolume sampling─requiring only a microvolume (around 20-40 μL) or a single droplet─but also facilitates direct micro-electroanalysis in a short time. To evaluate its capabilities, the mini-voltammetric cell was optimized for trace analysis of nitrite ions and demonstrated linear responses in the ranges of 20-150 and 150-1200 μM, with an acceptable limit of detection (LOD) of 18.40 μM, meeting both WHO and EPA standards for nitrite levels. Furthermore, it exhibited high selectivity, stability (up to 36 continuous measurements with only a 3.24% signal drop), and acceptable repeatability (RSD of 2.98%, n = 15). The analytical performance of this miniaturized tool was further assessed through the sampling and detection of nitrite ions in various real samples with different matrixes: (1) urine samples, for the fast diagnosis of urinary tract infections (UTIs), where nitrite ions are detected as biomarkers of UTIs; (2) river water polluted with agricultural waste, where nitrite ions serve as pollutants from nitrogen fertilizers; and (3) on the hands and in forensic investigations, where nitrite ions are detected as indicators of gunshot residue, crucial in crime scene examinations. All real samples were analyzed using the standard addition method and recovery tests, yielding acceptable results. Additionally, the proposed mini-analytical tool was evaluated for its sustainability and applicability using two recognized metrics: The Green Analytical Procedure Index (GAPI) and the Blue Applicability Grade Index (BAGI). The results confirmed that this method can be classified as both a green analytical method and highly applicable. Finally, the practical results demonstrated that the proposed miniaturized electroanalytical tool exhibits reliable performance, high sensitivity and selectivity, and fast response in the on-site microanalysis of nitrite, without the need for any reagents or complex sampling steps, across different real samples (such as clinical, forensic, and environmental samples). We believe the proposed mini-voltammetric cell could be used as an alternative to current detection methods, and with suitable modifications, it could be adapted for the microanalysis of other applications and (bio)targets with small volumes in the near future.

Advancements in maize cultivation: synergistic effects of dry atmospheric plasma combined with plasma-activated water

Abstract In this study, we investigate the effects of pre-germinative and post-germinative plasma treatments, applied separately or in combination, to improve maize germination and early seedling development. Pre-germinative treatment consists of priming the seeds with a dry atmospheric plasma (DAP) generated by a dielectric barrier device, characterized by minimal radiative emission, low electrical power (4 W) and high emissions of O, OH and NO radicals. Post-germinative treatment, known as plasma-activated water (PAW), uses a single pin electrode device (SPED) to generate a DC discharge that features a power of 126 W and produces large amounts of OH radicals. The resulting PAW, after 5 min of SPED treatment, induces a slight acidification and increased concentrations of nitrate ions (from 24 to 250 mg l−1), nitrite ions (from less than 0.1 to 56.1 mg l−1) and hydrogen peroxide (from 0.3 to 18.5 mg l−1). Results indicate that DAP applied on maize seeds for 20 min boosts their germination rate by up to 90% (versus only 65% for untreated seeds) while reducing the median germination time by 37.5%. Then, seedling growth monitoring is achieved on control, DAP, PAW and DAP + PAW groups to assess stem length, hypocotyl length, leaf count, collar diameter and fresh/dry mass. The DAP + PAW group shows the most robust growth, demonstrating a synergistic effect of the combined treatments, particularly with significantly longer stem lengths. Additionally, physiological analyses of seedling leaves indicate a decrease in chlorophyll content despite enhanced growth, while fluorescence microscopy reveals a reduction in stomatal density in leaves treated with DAP and PAW, especially in the combined treatment group, potentially impacting photosynthetic efficiency and water regulation.

Ammonia Synthesis with Visible Light and Quantum Dots.

Light-assisted synthesis of ammonia from nitrate and nitrite sources is a sustainable approach to reduce the burden of the energy-intensive Haber-Bosch process. However, poor selectivity and the need for UV-active photocatalysts are the current bottlenecks in the synthesis of ammonia from nitrate and nitrite sources. Herein, we introduce selective visible-light-driven ammonia production from nitrate and nitrite ions with indium phosphide quantum dots (InP QDs) as the photocatalyst. The presence of catalytic indium sites and microenvironment modulation through an interplay of catalyst-reactant interactions resulted in efficient and selective ammonia formation under visible light. Ammonia was produced in an attractive yield of ∼94% in both aqueous and gaseous phases within 2 h of visible-light irradiation at room temperature. A decent formation of ammonia was observed under sunlight as well, strengthening the translational prospects of InP QD photocatalysts. Mechanistic investigations ascertained a negligible role of competing hydrogen evolution in direct nitrate reduction, confirming the active participation of photoexcited charge carriers from InP QDs in the ammonia synthesis. Kinetic studies revealed the energetically challenging nitrate-to-nitrite conversion as the rate-determining step, with subsequent reactions proceeding with ∼100% conversion to yield ammonia. A series of experiments concluded that water is the proton source in the InP QD-photocatalyzed synthesis of ammonia. Our study shows the impact of the rationally designed core and surface of InP QD-based photocatalysts in developing sustainable routes to produce ammonia beyond the Haber-Bosch process.

Research on the functional properties and extraction methods of dietary fiber

Abstract. Dietary fiber is a form of polysaccharide that does not yield energy and cannot be fully broken down and absorbed by the digestive enzymes in humans. Furthermore, the human body is unable to produce it; instead, food produced from plants is the only source of it. There are specific species of gut microbiota that ferment dietary fiber, producing short-chain fatty acids, monosaccharides, and gases as byproducts. Dietary fiber has both physicochemical (solubility, viscosity, absorption, water holding capacity, and oil holding capacity) and functional properties (glucose adsorption, cholesterol adsorption, and nitrite ion adsorption ). Dietary fiber can be extracted from plant using a variety of techniques, including chemical, mechanical, and enzymatic methods; however, these techniques have significant shortcomings, such as narrow extraction zones and poor extraction quality. Through the course of the last few centuries, the amount of dietary fiber has significantly decreased, which has led to unhealthy human conditions like obesity, cancer, type 2 diabetes, and constipation. Nowadays, these Dietary fibers, therefore, are given great attention because of their physicochemical and functional properties which are vital for human health. These products from plant resources and fruits can be further used for food manufacturing and processing.

Ionic composition of snow cover on the territory of Siberia and the Far East

Long-term (from 2007 to 2022) observations of the dynamics of acidity, mineralization and ionic composition of snow cover in remote mountainous and lowland landscapes of Northern Asia were carried out. As a result, spatiotemporal changes in the molar concentration of basic (Ca2+, Mg2+, HCO3-, Cl- and SO42-) and nitrogen-containing (NH4+, NO3- and NO2-) ions were analyzed. It turned out that during the entire observation period, bicarbonate ions prevailed in all monitoring regions, even near the sea coasts, where there is an intensive intake of sulfate and chloride ions into the atmosphere. Until 2012, the molar concentration of these three anions was characterized by higher values, which decreased 3–8 times in subsequent years, this is especially noticeable for bicarbonate ions and to a lesser extent for chloride ions. The molar concentration of nitrogen-containing ions in the snow cover of Northern Asia was at a low level (especially nitrite ions). Ammonium ions were predominant throughout the observation period (especially in mountainous landscapes) and only in some years – nitrate ions.

A generic novel HPLC method for the determination of nitrite ion by direct derivatization

BackgroundThis research introduces a novel, simplified method to quantify carcinogenicity generating nitrite in Key Starting Materials (KSMs) and specific drugs. Since no straightforward approach exists in the literature, this method aimed to fill the lacunae and fulfill safety assessments in pharmaceutical applications. MethodThe developed method employs a direct and simple derivatization procedure using High-Performance Liquid Chromatography (HPLC). The conditions include Zorbax SB C8 column (stationary phase), trifluoroacetic acid (TFA): water: acetonitrile at 0.05:55:45 % v/v as mobile phase A, and TFA: acetonitrile at 0.05:100 % v/v as mobile phase B in a gradient elution at 0.8 mL/minute flow rate. The gradient program is time/%A, 0/100, 10/100, 15/0, 19/0, 20/100, 25/100. Significant findingsA simple method was established to regulate the nitrite ion levels in KSMs and certain medications. By making a fine-tuning to chromatographic conditions, this method can quantify nitrite content in any pharmaceutical materials, thus, demonstrating its generic applicability. The developed method was validated according to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. It is linear and accurate from the limit of quantitation (LOQ) to 150 % (i.e., 0.5 to 1.5 ppm) of the specified limit (1.0 ppm). The LOQ and limit of detection (LOD) for this method are 0.5 and 0.1 ppm, respectively.

Tracking the electrocatalytic activity of Au@Ag core–shell nanoparticles for nitrite oxidation via single-entity electrochemistry

Single-entity electrochemistry (SEE) has been extensively utilized for analyzing various substances, elucidating their mechanisms, and predicting particle behavior on electrode surfaces. In this paper, we propose a novel method for analyzing the electrochemical reactions between core–shell nanoparticles (NPs) and nitrite ions at the single-particle level. This method employs single Au@Ag core–shell NPs, nitrite ions (NO2-), and a carbon ultramicroelectrode (C-UME), utilizing the electrochemical oxidation of NO2- ions upon collision with individual core–shell nanoparticles on the C-UME surface. Au@Ag core–shell NPs with different ratios were synthesized to achieve the effective oxidation of NO2- ions, and their electrochemical properties were analyzed. Various parameters, such as applied potential and NO2- ion concentration, were adjusted in chronoamperometric experiments to analyze the resulting signals. This study is expected to significantly contribute to the analysis of oxidation/reduction, dispersion, and catalytic properties of various NPs, particularly core–shell NPs.

Effects of combining ultrasound and dual enzymolysis with hydroxypropylation, acrylate grafting, or phosphate grafting on the physicochemical and functional properties of oil palm mesocarp expeller dietary fiber

Oil palm mesocarp expeller is an abundant and low-cost dietary fiber resource, but its poor hydration and adsorption properties limit its utilization in foods. Therefore, ultrasound and enzymolysis combined with hydroxypropylation, acrylate grafting, or phosphate grafting were used to improve the adsorption properties of oil palm mesocarp expeller fiber (OPMEDF) for the first time. The results revealed that these composite modifications made the microstructure of OPMEDF more porous, and significantly increased its soluble fiber content, surface area, hydration properties, and sorption abilities of glucose, nitrite, copper, and lead ions but decreased its brightness. OPMEDF modified by ultrasound, enzymolysis, and acrylate grafting had the highest content of extractable polyphenol and sorption abilities on oil and nitrite ion. OPMEDF subjected to ultrasound, enzymolysis, and phosphate grafting showed the highest water-swelling volume (3.84 mL g−1) and sorption abilities of copper (II) and lead (II) ions. Notably, OPMEDF modified by ultrasound, enzymolysis, and hydroxypropylation exhibited the highest soluble fiber content (14.72 g∙100 g−1), water-retention ability (5.22 g g−1), viscosity (13.90 cp), and glucose adsorption capacity (38.18 g∙100 g−1). These results indicated that these composite modifications are good options to improve the adsorption capacities of OPMEDF and can expand its potential hypoglycemic and hypolipidemic effects.

Biochemical parameters and oral fluid microcrystallization in young patients who use a vape device

The study aims s are researching the negative effect of nicotine-containing vapes on physical and chemical parameters of oral fluid and morphotyping of dried oral fluid drop among young somatically healthy individuals. Material and methods. The study included 20 people between the ages of 18 and 24 years old, divided into 2 groups: the «Vape» group (n=12) human only nicotine-containing vape for at least 2 years and the «Control» group (n=8) not human nicotine in any form. pH, thiocyanate (rhodonide) concentrations, surface tension, oral fluid volume, hygiene indices and periodontal indices were studied. The morphotype of dried oral fluid drop was analyzed. Results. In the «Control» group in 3 cases gingivitis chronic K05.1 was diagnosed, and in the patients of the «Vape» group in 9 cases. It was found that the rhodonide content in the «Vape» group before «vaping» was higher than in the «Control» group and was Me= 1.31 mM/L and Me=0.58 mM/L respectively p=0.012. After vape application, the concentration of rhodonides in oral fluid increased in 1.16 times (p=0.0077), nitrite ions content from Me=0.09 mg/L to Me=0.32 mg/L (p=0.07), pH increased to Me=7.64; (LQ=7.45; HQ=7.67) (p=0.07) (p=0.07). The volume of RW in the Vape group remains 2.8 times smaller than in the Control group (p=0.012). The microcrystallization pattern of the oral fluid drop in the «Vape» group before «steaming» more often corresponded to type II A, and after «steaming» in 33.4% cases type III was determined, in 25% – type II B. Conclusions. Thus, in «vapers» of 18–24 years old statistically reliable reduction of oral fluid volume, high values of hygiene index shift of acid-base balance in the direction of alkalosis creates conditions in the oral cavity for the development of periodontal diseases and the emergence of cariesogenic situation. There was an increase in the concentration of rhodanide and nitrite ions, which in combination with other components of vape aerosols can be considered as procarcinogens, syncarcinogens and cocarcinogens. The change in the morphology of facies pattern, type of microcrystallization of oral fluid drop in the dynamics of vape use corresponds to the vector of changes observed in other inflammatory diseases of the oral cavity

Fe/Cl/N triply-doped bamboo-like structure wrapped with Fe3C nanoparticles for electrochemical selective nitrite detection

Nitrite is commonly found in the natural environment and in everyday human activities. However, excessive nitrite consumption can potentially harm human health. Consequently, it is crucial to develop a reliable and sensitive method for nitrite detection. In this work, trichloroacetic acid functionalized Cl-Fe-MIL-88B metal-organic framework is obtained through nucleophilic reaction between animated Fe-MIL-88B and trichloroacetic acid, which is then annealed with melamine in an N2 atmosphere to produce the Fe/Cl/N triply-doped bamboo-like carbon nanotubes (CNTs) wrapped with Fe3C nanoparticles. Owing to the effective doping of Fe/Cl/N elements, the charge distribution and chemical activity of the bamboo-like structure are tailored, greatly improving the conductivity and facilitating electron transfer of the composite for potential electrocatalytic reaction. The Fe3C nanoparticles wrapped inside the CNTs contribute to expose more active sites and provide effective surface area. Accordingly, the Fe/Cl/N doped bamboo-like structure modified glassy carbon electrode shows excellent electrochemical nitrite sensing properties with a high sensitivity of 1060 µA cm−2 mM−1, a low detection limit of 0.61 µM in a wide linear concentration range of 5–5000 μM, as well as good anti-interference and long-term stability. Also, the electrochemical sensor has a satisfactory recovery rate for detecting nitrite ions in spiked milk samples. This work proposes a simple precursor chlorination and pyrolysis strategy to obtain metal-filled bamboo-like structure with high electrical conductivity and electrocatalytic properties, endowing great potential in food safety and environment monitoring.

Electrokinetics of Nitrite to Ammonia Conversion in the Neutral Medium Over A Platinum Surface.

Polycrystalline Pt electrode was employed to selectively convert nitrite ions ( ) into useful nitrogenous compound through electrochemical reduction reaction in neutral medium. According to adsorptive stripping analysis, the reduction process produced nitric oxide (NO) on the surface of Pt electrode. The spectroscopic test and gas chromatographic studies discovered the presence of ammonia (NH3) in the electrolyzed solution, suggesting the transformation of adsorbed NO into NH3 during the reverse scan. Scan rate dependent investigation was performed to elucidate kinetic information relating to this reaction on Pt surface. From Ep vs scan rate (υ) and jp vs υ (logarithmic plot), it was found that the conversion of ion into NO is an irreversible reaction which relies on the diffusion of ions to electrode surface. The Tafel analysis unveiled that the first electron transfer sets the overall reaction rate, having formal reduction potential, E0'=-0.46 V and standard heterogeneous rate constant, k0= cm s-1. Reductive transfer coefficient (α) is another kinetics parameter, which was found to be approximate 0.77 from the difference between Ep and Ep/2 of the voltammograms obtained over scan rate range 0.005 V s-1 to 0.250 V s-1, indicating a stepwise process. According to temperature-dependent voltammograms, the nitrite reduction reaction on Pt had a calculated activation energy of about 19.8 kJ mol-1 and a pre-exponential factor of about 8.39×103 mA cm-2.

An Ultra‐Sensitive Electrochemical Sensor for Nitrite Based on Green Synthesized Gold Nanoparticles Using Colocasia Esculenta Extract

AbstractSeeking to establish a novel, eco‐friendly and ultra‐ sensitive electrochemical nitrite sensor, we have fabricated fluorine doped tin oxide (FTO) electrode with green synthesized gold nanoparticles (AuNPs) from gold salt and taro plant (Colocasia esculenta) extract (Taro_AuNPs/FTO). Different morphological and elemental analysis were conducted to undermine morphological condition and shapes of AuNPs. Further, electrochemical studies were performed for enabling observation on the modification as well as interaction between nitrite ion and AuNPs on the modified FTO. Furthermore, the performance of Taro_AuNPs/FTO sensor was evaluated using DPV technique and the limit of detection (LOD) was 0.923 nmol L−1 (S/N=3) having sensitivity of 0.00503 μA mM−1 cm−2 within 5–500 μmol L−1. Additionally, an insightful mechanistic overview was highlighted about interacting nitrite on the modified electrode surface. Finally, interference test, stability, reproducibility and real sample analysis were conducted to establish the effectiveness of Taro_AuNPs/FTO electrochemical senor for environmental application.

Extraction Method Effects on Structural Properties and Functional Characteristics of Dietary Fiber Extracted from Ginseng Residue.

In this research, the dietary fibers (DFs) from ginseng residue were extracted by employing three different extraction methods (alkaline: AL, acidic: AC, enzymatic: EN). The extracted DFs were characterized in terms of their structural and functional properties. The results clearly showed that, regardless of the extraction methods, all DF samples exhibited representative infrared spectral features. The DF extracted by AC (citric acid) had more porous structures with a looser configuration, in conjunction with high apparent viscosity, whereas the DF extracted by EN (α-amylase and protease) exhibited higher thermal stability. Moreover, the monosaccharide composition of the DF samples was significantly influenced by the extraction method type. The DF from ginseng residue extracted by AC had the highest functional properties, such as water holding capacity (8.16 g/g), oil holding capacity (3.99 g/g), water swelling capacity (8.13 g/g), cholesterol-absorption capacity (12.85 mg/g), bile acid absorption capacity (91.51 mg/g), nitrite ion absorption capacity (124.38 ug/g at pH 2.0), glucose absorption capacity (52.67 mg/g at 150 mmol/L), as compared to those of DF extracted by the EN and AL (sodium hydroxide) methods. Hence, ginseng residue-derived DF extracted by the AC method may be potentially employed in the preparation of functional food ingredients.

Effects of acid, alkaline and enzymatic extraction methods on functional, structural and antioxidant properties of dietary fiber fractions from quince (Cydonia oblonga Miller)

In this study, quince soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were obtained by acid extraction, enzyme extraction and alkaline extraction methods. The acid extracted DF displayed higher results compared to enzyme and alkaline extraction methods in terms of water holding capacity (15.97 g/g SDF), oil holding capacity (1.05 g/g SDF) and nitrite ion adsorption capacity (92.83 mg/g SDF). The antioxidant activity and phenolic content of acid extracted IDF were significantly higher than the other quince DFs. In addition, quince DFs exhibited in vitro hypoglycaemic activity, exhibiting high glucose adsorption capacity (237 mg/g) and α-amylase inhibition activity (82 %). Similarly, acid extracted SDF of quince showed in vitro hypolipidemic activity, with cholesterol adsorption capacity of 155 mg/g and lipase inhibition activity of 36 %. The structures and thermal properties of quince DFs were characterized by FT-IR and TGA. Quince DFs with high functional properties might be suitable agents for functional food formulations, such as meat products, low-calorie fruit bars, flour mixtures, etc.

Nitrite: From Application to Detection and Development

Nitrite, a collective term for a group of inorganic compounds containing nitrite ions (NO2−), is widely present in the natural environment and in the human body. It has a wide range of applications in the medical, food and environmental fields, such as food additives, water treatment agents and drugs. However, the excessive intake of nitrite poses indirect carcinogenic, teratogenic and mutagenic risks to humans. With the in-depth study of the functional properties of nitrite, there is an increasing demand for accurate and efficient methods for its detection. This paper presents a review of methods for the detection of nitrite, which will cover different principles and technologies, including traditional methods, optical methods, electrochemical sensors, and biosensors, and their prospects. By comparing and evaluating the different methods, it will provide references and valuable suggestions for choosing the most suitable nitrite detection methods and the scientific selection of alternatives for nitrite.

Swift and Cost-Effective Detection of Nitrite in Environmental Samples Using Ru@Pt Modified PGE

The development of a straightforward method is crucial for detecting and quantifying nitrite ions within the surrounding environment. This study involves the electrochemical fabrication of a bi-metallic alloy composed of Ruthenium and Platinum on a graphene-modified pge, the first-ever electrodeposition on pencil graphite (RuNPs@PtNPs/Gr-CHI). This study aims to establish a highly responsive and specific approach for identifying nitrite ions while demonstrating the efficacy of a commercially available pencil graphite electrode in detecting this environmental contaminant. The prevalence and structural characteristics of bimetallic nanoalloy particles are confirmed through X-ray diffraction, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The composite exhibited a core–shell shape at a size of 26.998 nm. The electrooxidation of nitrite at RuNPs@PtNPs/Gr-CHI/PGE was investigated using differential pulse voltammetry. The results demonstrated a satisfactory linear relationship from 0.025 mM to 1.625 mM. The method revealed a low detection limit of 0.33 μM. The composite electrode exhibited favorable outcomes regarding selectivity, sensitivity (25.5 μAμM−1cm−2), and repeatability, which are desirable characteristics of the electrochemical sensor material. The constructed electrode underwent testing for five weeks to determine the stability. The suggested sensor’s capability is demonstrated by detecting nitrite ions in real samples such as water, soil, and fruit juice.

Health Risk Assessment of Nitrate, Nitrite, and Fluoride Ions in Water Reservoirs of Mehriz, Iran in 2023

Introduction: High concentrations of nitrate, nitrite, and fluoride in drinking water can cause adverse health effects. This study aims to investigate concentration and health risks assessment of nitrate, nitrite, and fluoride ions in water reservoirs of Mehriz city and Bahadoran district. Materials and Methods: Monthly sampling was done from water reservoirs of Mehriz city and Bahadoran district for 6 months. Nitrate, nitrite, and fluoride concentrations were measured in the samples using a spectrophotometer. Then, health risk assessment and sensitivity analysis were performed on the obtained data using Crystal Ball software and Monte Carlo simulation method. Results: Nitrate, nitrite, and fluoride concentrations were lower than the standard limitation in all of the studied areas. Risk assessment findings indicated that hazard quotient (HQ) values of nitrite in Miankoh-Movahedin, Bidok and Bahadoran water reservoirs were less than 1 for all age groups. HQ values of nitrate were also below 1 for all age groups except children. HQ values of fluoride in Bahadoran water reservoir were below 1 for all age groups except children. Conclusion: Health risk of consuming water containing nitrates and fluorides is high for children. Based on sensitivity analysis, the concentration of nitrate and fluoride in drinking water is the key factor in raising health risks. Reducing nitrate and fluoride concentrations in drinking water can reduce health risks in the population.