Nitrite Ions In Water Research Articles

Solvent-Directed Transformation of the Self-assembly and Optical Property of a Peptide-Appended Core-Substituted Naphthelenediimide and Selective Detection of Nitrite Ions in an Aqueous Medium.

This study vividly displays the different self-assembling behavior and consequent tuning of the fluorescence property of a peptide-appended core-substituted naphthalenediimide (N1) in the aliphatic hydrocarbon solvents (n-hexane/n-decane/methyl cyclohexane) and in an aqueous medium within micelles. The N1 is highly fluorescent in the monomeric state and self-aggregates in a hydrocarbon solvent, exhibiting "H-type" or "face-to-face" stacking as indicated by a blue shift of absorption maxima in the UV-vis spectrum. In the H-aggregated state, the fluorescence emission of N1 changes to green from the yellow emission obtained in the monomeric state. In the presence of a micelle-forming surfactant, cetyl trimethylammonium bromide (CTAB), the N1 is found to be dispersed in a water medium. Interestingly, upon encapsulation of N1 into the micelle, the molecule alters its self-assembling pattern and optical property compared to its behavior in the hydrocarbon solvent. The N1 exhibits "edge-to-edge" stacking or J aggregates inside the micelle as indicated by the UV-vis spectroscopic study, which shows a red shift of the absorption maxima compared to that in the monomeric state. The fluorescence emission also differs in the water medium with the NDI derivative exhibiting red emission. FT-IR studies reveal that all amide NHs of N1 are hydrogen-bonded within the micelle (in the J-aggregated state), whereas both non-bonding and hydrogen-bonding amide NHs are present in the H-aggregated state. This is a wonderful example of solvent-mediated transformation of the aggregation pattern (from H to J) and solvatochromism of emission over a wide range from green in the H-aggregated state to yellow in the monomeric state and orangish-red in the J-aggregated state. Moreover, the J aggregate has been successfully utilized for selective and sensitive detection of nitrite ions in water even in the presence of other common anions (NO3-, SO42-, HSO4-, CO32-, and Cl-).

Solvation Shell of the Nitrite Ion in Water: An Ab Initio Molecular Dynamics Study.

We performed ab initio molecular dynamics simulation of a nitrite ion in water to investigate the structural and dynamical properties of its hydration shell. The nitrite ion is found to exhibit strong asymmetry toward hydrogen bonding due to its two different types of hydrogen bond acceptor sites. This difference is better captured through further partitioning of the hydration shell into its proximal and distal regions. The frequency shifts of the stretch modes of hydration shell water reveal that the nitrogen site forms a stronger hydrogen bond than its oxygen sites with the latter forming hydrogen bonds, which are similar in strength to that between a pair of water molecules. The escape dynamics of water from the hydration shell is found to be rather slow, which seems to classify the nitrite ion as a structure-maker. However, the dynamics of orientational and hydrogen bond relaxation reveal a faster mobility of water molecules in the hydration shell than bulk water in spite of strong ion-water interactions. It is found that the nitrite ion can hold water molecules in its solvation shell and still make them rotate fast in its vicinity through switching of their hydrogen bonds between its nitrogen and oxygen acceptor sites. The dipole moment of the solute in water is also calculated in the present study.

Green synthesis of N-doped carbon quantum dots for the detection of nitrite ion in water sample

In this work, a green hydrothermal method was used to synthesize nitrogen-doped carbon quantum dots (N-CQDs) from Ecuadorian shrimp shell. X-ray diffraction (XRD) pattern showed that N-CQDs had an amorphous carbon peak. Both Fourier transform infrared (FT-IR) spectra and X-ray photoelectron (XPS) spectra indicated the presence of C, O and N in N-CQDs. The elemental analysis revealed that the weight percentage of C, H and N in N-CQDs are 45.7%, 6.9% and 13.2%, respectively. Transmission electron microscopy (TEM) image demonstrated N-CQDs had an average size of 3 nm and spherical shape. While quinine sulfate with 54% fluorescent quantum yield was used as a reference, the quantum output of N-CQDs was calculated to be 23.7%. Ultraviolet-visible absorption spectra of N-CQDs showed that the maximum absorption wavelength was 275 nm. Photoluminescence (PL) spectra of N-CQDs displayed highest PL intensity at excitation and emission wavelengths of 323 and 407 nm, respectively. The results showed that the synthesized samples were N-CQDs. N-CQDs can be used as a fluorescent probe for nitrite ions in water. However, nitrite ion was not detected in Hu County River water and Xi’an tap water. This may be due to the absence of nitrite ion in the selected water samples.

Phototransformation of mefenamic acid induced by nitrite ions in water: mechanism, toxicity, and degradation pathways.

Here, we evidenced the photo-induced degradation of mefenamic acid, a nonsteroidal anti-inflammatory drug, through the 254-nm light excitation of nitrite. The results demonstrated that the photodegradation of mefenamic acid was enhanced, and the mefenamic acid photodegradation rate significantly increased, from 0.00627 to 0.0350 min(-1) as the nitrite was increased from 0 to 0.5 mmol L(-1). The photodegradation rate increased from 0.0287 to 0.0512 min(-1) as the pH was elevated, from 5.0 to 10.0. The actual second-order rate constant for the reaction of mefenamic acid with ·OH was investigated to 1.079 × 10(10) M(-1) s(-1) according to steady-state ·OH concentration of 3.5 × 10(-14) mmol L(-1) and the contribution to the rate of ·OH of 67.1%. The photoproducts were identified using HPLC/MS/MS, and possible nitrite-induced photodegradation pathways were proposed by hydroxylation, dehydrogenation, hydration, nitrosylation, and ketonized reactions. The toxicity of the phototransformation products was evaluated using the Microtox test, which revealed that the photoproducts were more toxic than mefenamic acid for the generation of nitrosation aromatic compounds.

Turn-On Type Fluorogenic and Chromogenic Probe for the Detection of Trace Amount of Nitrite Ion in Water

A rhodamine B-based fluorescent probe for nitrite ion () has been designed, synthesized, characterized and its properties for recognition of were studied. Nearly non fluorescent probe upon reaction with nitrite ion significantly triggered the fluorescence. Fluorescence response is based on ring opening of the spirolactam of rhodamine B phenyl hydrazide showing maximum absorbance at 552 nm and maximum emission at 584 nm. Probe 3 exhibited high sensitivity and extreme selectivity for nitrite ion over other common ions and oxidants (, , , , , , , , ) examined in methanol water (1:1, v/v) at pH 7.0. The probe might be a new efficient tool for detection of nitrite ion in natural water and biological system.

A reaction based turn-on type fluorogenic and chromogenic probe for the detection of trace amount of nitrite in water

A turn-on fluorescent probe for the detection of nitrite ion in water is developed based on diazotization reaction of the amino group of the probe in an acidic solution (pH 1). The probe responds selectively to nitrite ion over various other anions with a turn-on type fluorogenic change from colorless to orange by the formation of rhodamine B via an analyte triggered fragmentation process. The fluorescence titration is complete within 1h with 1 equivalent of nitrite ion. The probe is highly efficient, cost-effective and shows a detection limit of 4.6ppb.

Advanced Technology Wastewater Treatment of Nitrite Ions

The main reason for high concentration of nitrite ions in water is the existence of sources of industrial and agricultural pollution. Contamination of drinking water, juices, wine and other liquids of nitrite ions as a result of improper use of nitrogen fertilizers has an adverse effect on living organism, because under the influence of enzymes nitrite ions in living organisms form high carcinogenic nitrosamines, and the interaction of nitrite ions from blood hemoglobin causes such toxicity that leads to disease cyanosis [1]. Therefore removal of nitrite ions from water has received increased attention. The paper discusses an innovative wastewater treatment technology from the nitrite ion with hypochlorite produced during electrolysis.

A convenient and efficient protocol for the synthesis of 4(1 H)-cinnolones, 1,4-dihydrocinnolines, and cinnolines in aqueous medium: application for detection of nitrite ions

3-Aryl/alkyl-4(1 H)-cinnolones are obtained in one step from 2-aryl/alkylethynyl aniline by reaction with sodium nitrite and dilute hydrochloric acid via Richter cyclization. The alkyl cinnolones on reduction with Sn/HCl furnish 1,4-dihydro-3-alkylcinnolines, which are converted to 3-alkylcinnolines by treatment with NaNO 2/HCl/KI. The whole process is carried out in aqueous medium at ambient temperature within a short reaction period. The reaction of 2-phenylethynyl aniline exhibits yellow color with UV absorbance at 391 nm and has been successfully tested for the detection of nitrite ions in water at parts per million concentration.

Effective indirect enrichment and determination of nitrite ion in water and biological samples using ionic liquid-dispersive liquid–liquid microextraction combined with high-performance liquid chromatography

An ionic liquid dispersive liquid–liquid microextraction high-performance liquid chromatography (IL-DLLME-HPLC) method for effective enrichment and determination of nitrite ion in water and biological samples was developed. The method was based on the reaction of nitrite ion with p-nitroaniline in the presence of diphenylamine in acid media and IL-DLLME of azo product. The optimization of reaction and extraction conditions, such as kind and concentration of acid, reaction time, volume of reaction solvent, temperature, kind of extraction and dispersive solvent, volume of extraction and dispersive solvent, addition of salt, extraction and centrifugal time were studied. Under the optimal conditions, 1-octyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL-DLLME procedure provided high enrichment factor of 430 and good extraction recovery of 91.7% for nitrite ion. The linearity was observed in the range of 0.4–500.0 μg L −1 with good correlation coefficient ( r 2 = 0.9996). The relative standard deviations (RSDs) for five replicate measurements varied between 1.5% and 4.8%. The limit of detection of the method (S/N = 3) was 0.05 μg L −1. The interference effect of some anions and cations was also tested. The developed method allowed achieving an excellent enrichment factor, yielding a lower LOD in comparison with other methods. Moreover, the proposed method was able to analyze nitrite ion in water and biological samples with satisfactory recovery ranged from 96.5% to 107.3%.

ChemInform Abstract: Facile Cyclization of 2‐Arylethynyl Aniline to 4(1H)‐Cinnolones: A New Chemodosimeter for Nitrite Ions.

ChemInformVolume 42, Issue 16 Heterocyclic Compounds ChemInform Abstract: Facile Cyclization of 2-Arylethynyl Aniline to 4(1H)-Cinnolones: A New Chemodosimeter for Nitrite Ions. Raju Dey, Dep. Org. Chem., Indian Assoc. Cultiv. Sci., Kolkata 700 032, IndiaSearch for more papers by this authorTanmay Chatterjee, Dep. Org. Chem., Indian Assoc. Cultiv. Sci., Kolkata 700 032, IndiaSearch for more papers by this authorBrindaban C. Ranu, Dep. Org. Chem., Indian Assoc. Cultiv. Sci., Kolkata 700 032, IndiaSearch for more papers by this author Raju Dey, Dep. Org. Chem., Indian Assoc. Cultiv. Sci., Kolkata 700 032, IndiaSearch for more papers by this authorTanmay Chatterjee, Dep. Org. Chem., Indian Assoc. Cultiv. Sci., Kolkata 700 032, IndiaSearch for more papers by this authorBrindaban C. Ranu, Dep. Org. Chem., Indian Assoc. Cultiv. Sci., Kolkata 700 032, IndiaSearch for more papers by this author First published: 24 March 2011 https://doi.org/10.1002/chin.201116161Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume42, Issue16April 19, 2011 RelatedInformation

Facile cyclization of 2-arylethynyl aniline to 4(1H)-cinnolones: a new chemodosimeter for nitrite ions

2-Arylethynyl anilines undergo very fast reaction (5min) with nitrite ions in aqueous acidic media to produce 4(1H)-cinnolones which exhibit yellow color and UV absorbance at 391nm. This reaction is irreversible and has been successfully tested for the detection of nitrite ions in water at ppm concentration. Thus, 2-phenylethynyl aniline serves as a chemodosimeter. An efficient and general method for the synthesis of 4(1H)-cinnolones has been developed based on this reaction.

The Stepwise Injection Analysis as a New Opportunity for Automation of Chemical Analysis of Liquid, Gaseous and Solid-Phase Samples

In the article, various methods of flow injection and sequential injection analyses are considered. The relative advantages and disadvantages are investigated. The stepwise injection analysis is proposed as a new universal flow method of analysis which means maximum strict reproduction of all the analytical stages which are typical for automated stationary methods. The opportunities of the new method which can be applied to the sample analysis in any aggregative state are illustrated by the examples of phosphateions in urine, anionic surfactants and nitrate- and nitrite-ions in water, hydrogen sulfide in hydrocarbon gases, and phosphates in water-soluble mineral fertilizer.

Micellar catalysis in the systems arylamine-diphenylamine-NO 2 −

By methods of UV and IR spectroscopy and thermogravimetry reactions of diazotizaion and azo coupling were studied in the systems of primary arylamine (p-nitro-, p-carboxy- and p-sulfoaniline)- diphenylamine -nitrite ion in water and micellar media on the basis of surfactants. The micellar catalysis effect of sodium dodecylsulfate in the micellar media was revealed. Rate of diazotization was shown to be independent of the surfactants of various types. Formation of ionic associates of azo dyes with dodecylsulfate anions in premicellar region was established and physicochemical characteristics of the associates were estimated.

Catalytic Oxidation of Ammonium Ions with Nitrite Ions in Water over Metallic Platinum Supported on Titanium Dioxide at a Mild Reaction Temperature

Abstract Titanium dioxide-supported platinum catalyst, which was pretreated with H2 at 353 K in a reactor just before the reaction, exhibited extremely high activity toward the oxidation of ammonium ions with nitrite ions into nitrogen in water at 353 K.

Phototransformation of monuron induced by nitrate and nitrite ions in water: Contribution of photonitration

The nitrate and nitrite-induced phototransformation of monuron in aqueous solution has been investigated using 300–450 nm light irradiation. The degradation kinetics was estimated under various conditions of concentrations of substrate and inducer, oxygen content and pH. From the numerous photoproducts identified using LC–ESI-MS–MS and their evolution curves a degradation scheme was proposed. Besides oxidation of the N-terminus group (major pathway in the presence of NO 3 −) and a minor contribution of direct photolysis, the other photoproducts originated from Cl/OH substitution, regiospecific hydroxylation and/or nitration of the phenyl ring. The two last processes occurred competitively under the NO 3 − conditions even at “environmental” concentrations of the inducer yielding significant levels of nitro-derivatives. Their production was found to be oxygen-dependent in contrast to the NO 2 − conditions.

Novel Nitrite Membrane Sensor Based on Cobalt(II) Salophen for Selective Monitoring of Nitrite Ions in Biological Samples

A novel PVC-based membrane sensor based on the Co(II)-salophen complex (CSC) is described. The electrode revealed a Nernstian response over a wide nitrite ion concentration range (1.0×10−6–1.0×10−1 M). The detection limit of the sensor is 8.0×10−7 M. The best performance was obtained with a membrane composition of 33% PVC, 61% ortho-nitrophenyloctyl ether, 3% cobalt(II)-salophen, and 3% hexadecyltrimethylammonium bromide. The potentiometric response of the sensor is independent of the pH of solution in the pH range 4.5–11.9. The electrode exhibits a very fast response time and good selectivity over a variety of common inorganic and organic anions, including fluoride, bromide, iodide, sulfite, nitrate, thiocyanate, thriiodide and perchlorate. The selectivity behavior of the proposed sensor shows substantial improvements compared to the previously reported electrodes for nitrite ion. The membrane sensor can be used for at least 2 months without any divergence in potential. The electrode was successfully applied to the monitoring of nitrite ion in water, sausage, flour, wheat, cheese and milk.

Evidence for the Generation of Singlet Oxygen ( 1 O 2 , 1 ? g ) from Ozone Promoted by Inorganic Salts

Evidence for novel chemical sources of singlet oxygen based on the conversion of ozone by tin(II) in acetic acid or nitrite ions in water was found by screening a selection of inorganic salts by means of a sensitive detector for exothermic processes (SEDEX) and a N2-cooled Ge-diode for singlet oxygen luminescence measurements.

Reduction of nitrite-ions in water over Pd-supported on structured fibrous materials

The catalytic hydrogenation of nitrite in water to nitrogen over Pd-supported on different woven fibrous materials is studied. Low porosity carbon fibers, low porosity D-type glass fibers and composite (glass covered by γ-aluminia) fibers are used. The dispersion of Pd is compared for different supports at various Pd-loadings and correlated with the catalytic activity. The ammonia as an undesired by-product was also observed and the main parameters suppressing its formation are discussed. A reactor concept based on woven fibrous catalysts is suggested and the main design parameters for the technical application are estimated.

Catalytic membrane in denitrification of water: a means to facilitate intraporous diffusion of reactants

Abstract The series of mono- and bi-metallic catalysts with Pd and/or Cu supported over γ-Al2O3 was investigated with respect to reduction of nitrate and nitrite ions in water by hydrogen. Pronounced limitations of catalytic performance due to intraporous diffusion of the reactants were observed in the reaction. Catalytic membrane containing the Pd–Cu active component supported over macroporous ceramic membrane-support was prepared, investigated and applied to facilitate the intraporous mass transfer. Forced flow of the reacting solution through the membrane was revealed to increase the effective catalytic activity. The approach explored in this study offers a cost-efficient alternative to the conventional concept of catalytic water denitrification process in a slurry reactor, presuming fixed-bed type operation with macroporous catalytic membranes at high level of catalytic activity.

The near-UV absorption constants for nitrite ion in aqueous solution

The UV decadic molar absorptivities of nitrite ion in water were determined between 290 and 400 nm in 2-nm increments. The measured maximum absorptivity of 22.93 M cm −1 at 354 nm is in agreement with previous results. Using absorptivities obtained in this wavelength range, we calculated the first-order rate constant for the formation of OH radicals by the photolysis of aqueous nitrite in summer noon sunlight at 40°N. The resulted rate constants, 5.2 × 10 −5 s −1 for surface water and 1.04 × 10 −4 s −1 for cloud and rain water droplets, are twice the previously reported values. The environmental significance of these results is discussed briefly.