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[ACM Press the 2017 International Conference - Singapore, Singapore (2017.12.27-2017.12.29)] Proceedings of the 2017 International Conference on Information Technology - ICIT 2017 - The Detection of Nitrite Content in Bacon based on Hyperspectral Technique
摘要： As a common food additive, nitrite has been widely used in meet products such as bacon. However, when the content of nitrite in food is overproof, consumer’s health will be seriously endangered. To solve this problem, this paper takes bacon as the sample to research the feasibility of hyperspectral technique in nitrite fast detecting. The partial least- squares (PLS) is utilized to associate the nitrite content data obtained via hyperspectral technique with the data obtained via GB method, and then the nitrite content calculating model is built. After comparing several models that adopt different spectrum pre-processing methods, the research team find that the first-order derivative plus vector normalization model is the best, whose RMSECV is 0.251 and r2 is 0.972. The result proves that hyperspectral can be effectively used in nitrite content prediction.
关键词： Chinese bacon,PLS,Hyperspectral,Nitrite
更新于2025-09-23 15:23:52
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The design of a polyaniline-decorated three dimensional W18O49 composite for full solar spectrum light driven photocatalytic removal of aqueous nitrite with high N2 selectivity
摘要： Photocatalysis using solar energy is the most promising green technology for nitrite removal. However, effective photocatalytic performance is often challenged by the limited light absorption, utilization of expensive noble metals and undesired products (nitrate and ammonium). Here, we report for the first time that a full solar light response polyaniline-decorated three dimensional W18O49 composite (PANI@W18O49), a noble metal-free photocatalyst, possesses excellent photocatalytic activity for aqueous nitrite removal with high N2 selectivity. The prepared sample was thoroughly identified via XRD, Raman, FTIR, SEM, TEM, UV–vis DRS and PL. The catalytic results demonstrated that over 80% N2 selectivity (initial concentration 1.0 mM) was achieved through the PANI@W18O49 without sacrificial agent under 300 W Xe lamp irradiation for 60 min. Such advantages were attributed to the built-in junction between n-type W18O49 and p-type PANI, offering suitable redox levels of electron-hole pairs for NO2? reaction. The modification of PANI also benefited the light harvesting ability and activated carriers migration, the calculated rate constant of PANI@W18O49 is about four times as high as that of W18O49. The current study not only prepared a promising photocatalyst, but also provides new insights into improving the photocatalytic activity and N2 selectivity for nitrite treatment.
关键词： Nitrite,Polyaniline,Tungsten oxide,Full solar spectrum light driven,Photocatalysis
更新于2025-09-23 15:23:52
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Synthesis of novel azo group substituted polymeric phthalocyanine for amperometric sensing of nitrite
摘要： The novel tetraazo-bridged cobalt phthalocyanine polymer [poly(TazoCoPc)] was synthesized by oxy-bridge to extend the conjugation effect on the phthalocyanine molecule. Firstly, the ligand [phenyl-1,4-bisdiazenyl naphthalene-1-oxy] benzene 1,2-dicarbonitrile was prepared and it was characterized. Then, the polymeric phthalocyanine was prepared and characterized by elemental analysis, UV-Vis, FTIR, TGA, XRD and electrochemistry. Polymeric phthalocyanine and carbon nanoparticles (CNP) were mixed and used for modifying the glassy carbon electrode to fabricate the electrochemical voltametric and amperometric nitrite sensor. Composite of phthalocyanine polymer and CNP exhibits enhanced electrocatalytic behaviour for the oxidation of nitrite compared to pure polymeric phthalocyanine. The fabricated amperometric sensor exhibits excellent analytical performance for nitrite detection in the concentration range of 20 nM to 1 μM with a detection limit of 6 nM (S/N = 3) and a sensitivity of 0.137 mA/μM. The modified composite electrode is highly selective and it didn’t show any interference effect even in presence of excess interfering ions such as Mg2+, SO4 2-, K+, CO3 2-, NO3 -.
关键词： phthalocyanine polymer,nitrite sensor,amperometry,carbon nanoparticle,voltametry
更新于2025-09-23 15:21:01
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Infrared Spectroscopic and Kinetic Characterization on the Photolysis of Nitrite in Alcohol-Containing Aqueous Solutions
摘要： Nitrite is regarded as a potential OH and NO precursor in aqueous solution upon ultraviolet photolysis. A step-scan Fourier-transform interferometer was employed to collect the transient infrared difference spectra upon excitation of the sodium nitrite aqueous solution in the presence of methanol and ethanol upon 355 nm pulsed excitation. The photolytic intermediates were proposed to be NO and NO2 via the direct dissociation from NO2? and the rapid reaction of OH and NO2?, respectively. Coupled with the theoretical calculations of the absolute energies and harmonic wavenumbers of relevant species using B3LYP density functional theory with the C-PCM model to account for the medium effect of H2O, a transient band at 1860?2030 cm?1 could be attributed to dissolved N2O3 isomers that could be quickly generated from NO + NO2. On the basis of the predicted thermodynamics, the reactions of alcohols with N2O3 were less thermodynamically favorable than that of water, resulting in a slightly decelerated depletion rate of N2O3 in alcohol-containing aqueous solution. Comparing the transient population of N2O3 in the absence and presence of CH3OH or C2H5OH, the upper-bound bimolecular rate coefficient of NO or NO2 with alcohols is reported as 7.3 × 103 M?1 s?1 for the first time. The spectroscopic and kinetic evidence of the reactivity of alcohols with NO, NO2, and N2O3 are provided to augment the roles of alcohols and NxOy in solution or in aqueous aerosol photochemistry.
关键词： Alcohols,Kinetics,Nitrite,Infrared spectroscopy,Aqueous solution,Photolysis
更新于2025-09-23 15:19:57
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[IEEE 2019 16th International Multi-Conference on Systems, Signals & Devices (SSD) - Istanbul, Turkey (2019.3.21-2019.3.24)] 2019 16th International Multi-Conference on Systems, Signals & Devices (SSD) - Investigation of Laser Induced Graphene Electrodes Modified by MWNT/AuNPs for Detection of Nitrite
摘要： In this paper, a novel low cost electrode material for sensing is presented which demonstrates excellent electrochemical response to nitrite while being amenable to implementation in disposable point of care nitrite sensors. Laser induced grapheneous carbon (LIG) is based on a simple laser engraving method to fabricate electrodes by inducing conductive paths onto Kapton polymer substrate. The working electrode was modified by Gold Nanoparticles (AuNPs), multiwalled carbon nanotubes (MWCNT) and AuNPs/MWCNT. The modified electrodes were characterized by electron microscopy energy x-ray dispersive spectroscopy (SEM-EDX), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Surface morphology and electrochemical methods confirms confirm the successful implementation of LIG electrodes whose electrocatalytic performance is highly improved after modification. This suggests the synergetic effect between AuNPs and MWCNTs with the excellent conductivity and large specific surface area. By means of square wave voltammetry (SWV), the limit of detection of the proposed sensor is 6.75 μM, which is low enough for practical applications. In conclusion, AuNPs/MWCNT modified LIG electrodes demonstrated good electrochemical behavior and promising future use in disposable nitrite electrochemical sensors.
关键词： electrochemical sensing,nitrite detection,carbon nanotubes,gold nanoparticles,Laser induced graphene
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN) - Fukuoka, Japan (2019.5.26-2019.5.29)] 2019 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN) - Optical sensor array based on P(V) corroles for fluorometric detection of nitrite
摘要： Two [5,10,15-pentafluorophenyl corrole] phosphorous (V), (PFCorr), and [10-(4-trimhetylsilyphenyl)-5,15-dimesityl-corrole] phosphorous (V) (PCorr) were synthesized and tested as nitrite-sensitive ionophore. Fluorimetry studies on ligand sensitivity towards anions were carried out first in solution and then inside polymeric membrane optodes. The selective ligand fluorescence quenching was registered upon addition of --ions. The influence on the PFCorr optode response of the lipophilic sites functionalization was investigated. The sensor will be tested in natural (fresh and seawater) and fish farm waters in order to detect the effectiveness of nitrite assessment at recommended concentrations levels (less than 0.3 mg/L).
关键词： phosphorous(V) corrole ligands,natural (fresh and seawater) and fish farm waters analysis,nitrite fluorometric assessment
更新于2025-09-16 10:30:52
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Reflection Spectra of Composite Photonic Crystals Based on Anodic Alumina Filled with Ferroelectric Sodium Nitrite
摘要： Re?ection spectra of a composite one-dimensional photonic crystal (PC) based on porous anodic alumina ?lled with ferroelectric sodium nitrite have been recorded in the wavelength range of 400 to 1200 nm. Signi?cant spectral shifts of the ?rst and second stopbands are revealed for the composite PC. The stopband spectral half-width is found to decrease by a factor of four to ?ve. The possibility of applying composite alumina-based photonic crystals as selective narrowband mirrors is discussed.
关键词： reflection spectra,ferroelectric sodium nitrite,photonic crystals,anodic alumina,stopbands
更新于2025-09-12 10:27:22
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Study of Bi-directional detection for ascorbic acid and sodium nitrite based on Eu-containing luminescent polyoxometalate
摘要： Eu-containing polyoxometalate K13Eu(SiMoW10O39)2·28H2O (Eu-SiMoW) owns the stimu-chromic and photo-luminescence properties. An ingenious test of ascorbic acid (AA) and sodium nitrite (NaNO2) was carried out based on the dual properties of Eu-SiMoW in solutions. First, the redox reaction of Eu-SiMoW and AA generated the blue reduced Eu-SiMoW, accompanied by fluorescence quenching; then the redox reaction of the reduced Eu-SiMoW and NaNO2 made Eu-SiMoW back to its original pale yellow state with red luminescence. Accordingly, the content of AA and NaNO2 could be measured by the reversible change of color and luminescence of Eu-SiMoW. This bi-directional detection method is first discovered and proven to be a simple and effective method for the detection of AA and NaNO2. The proposed method exhibited a linear response range (LRR) from 0.1 to 0.9 mmol L?1 with a limit of detection (LOD) of 0.53 μmol L?1 in UV–vis spectra and 4.67 μmol L?1 in luminescence spectra for AA as well as a LRR from 0.05 to 0.4 mmol L?1 with a LOD of 1.16 μmol L?1 in UV–vis spectra and 5.39 μmol L?1 in luminescence spectra for NaNO2. Moreover, the fluorescence switching of Eu-SiMoW could be realized by reacting with reductant and oxidant through the redox reaction. The detection mechanism is considered as a fluorescence resonance energy transfer process between discolor component SiMoW and luminescence component Eu in Eu-SiMoW.
关键词： Ascorbic acid,Sodium nitrite,Bi-directional detection,Eu-polyoxometalate,Luminescence switching
更新于2025-09-10 09:29:36
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Inorganic Salts and Antimicrobial Photodynamic Therapy: Mechanistic Conundrums?
摘要： We have recently discovered that the photodynamic action of many different photosensitizers (PSs) can be dramatically potentiated by addition of a solution containing a range of different inorganic salts. Most of these studies have centered around antimicrobial photodynamic inactivation that kills Gram-negative and Gram-positive bacteria in suspension. Addition of non-toxic water-soluble salts during illumination can kill up to six additional logs of bacterial cells (one million-fold improvement). The PSs investigated range from those that undergo mainly Type I photochemical mechanisms (electron transfer to produce superoxide, hydrogen peroxide, and hydroxyl radicals), such as phenothiazinium dyes, fullerenes, and titanium dioxide, to those that are mainly Type II (energy transfer to produce singlet oxygen), such as porphyrins, and Rose Bengal. At one extreme of the salts is sodium azide, that quenches singlet oxygen but can produce azide radicals (presumed to be highly reactive) via electron transfer from photoexcited phenothiazinium dyes. Potassium iodide is oxidized to molecular iodine by both Type I and Type II PSs, but may also form reactive iodine species. Potassium bromide is oxidized to hypobromite, but only by titanium dioxide photocatalysis (Type I). Potassium thiocyanate appears to require a mixture of Type I and Type II photochemistry to ?rst produce sul?te, that can then form the sulfur trioxide radical anion. Potassium selenocyanate can react with either Type I or Type II (or indeed with other oxidizing agents) to produce the semi-stable selenocyanogen (SCN)2. Finally, sodium nitrite may react with either Type I or Type II PSs to produce peroxynitrate (again, semi-stable) that can kill bacteria and nitrate tyrosine. Many of these salts (except azide) are non-toxic, and may be clinically applicable.
关键词： potassium thiocyanate,potentiation by inorganic salts,potassium bromide,potassium iodide,sodium azide,antimicrobial photodynamic inactivation,potassium selenocyanate,sodium nitrite
更新于2025-09-09 09:28:46